I'll counter that with compare your T2 equipped rogue to your T5.

There's ~4% less crit (sockets reclaim some of that but nowhere near all).
Crit is not going to see the same heights in TBC as it did in 1.x

Bad comparison. If you're doing 50 base melee dps and gain 28 AP, you're now doing 52 base melee dps. If you say 20% crit that means 60 -> 62.4. 4% improvement. Now, if you're doing 200 base melee dps, it's 200 -> 202 and 240 -> 242.4, only 1% improvement. In the first case, 1% crit gains you .5 DPS (.833%), in the second 2 DPS (again, .833%). As 1% crit becomes more costly, 1% crit becomes more valuable over AP. Ratings may skew things in AP's favor, but it's certainly not vastly. You still need a balance of both for best DPS. The higher your base DPS is, the better crit is compared to AP.

As a matter of fact: my crit and hit were worse when I dinged 60 3 weeks ago then when I hit 70 yesterday. Though I might add that I tend to focus on hit since I'm combat specced (the synergy of hit gear, a fast offhand and combat potency is pretty strong). I also tried mutilate for one level but having a crit rate of about 21 % just doesn't cut it.

As far as itemization goes, TBC is insanely good for rogues. Most pre-TBC rogue gear had strength. TBC rogue gear doesn't -- all AP instead. It's as if rogues suddenly got 2 AP per str. I've only been 70 for three days, and already I'm down to only two pieces with strength on them, and those will be going away very shortly once I replace their enchants.

There was a reason why things like Cape of the Black Baron and Bracers of the Eclipse were used by raiding rogues way past epic drops being available in those slots -- leather with strength on it is, and fundamentally always has been, feral gear. TBC just drops rogue leather, while retail was rather stingy with it.

My crit is way down and AP hasn't budged. This is simply because I was in almost entirely T3 gear, which isn't replaceable for me yet (level 65 at the moment).

I don't see the big deal, really. If I want to keep my original stats, I can stay a 60 twink. But a 70 in blues would be stronger. Although my scaling stats are depleting (due simply to being overinflated in the first place), I'm getting access to new upgrades, new abilities, more talent points, a lot more HP. I'm still working towards becoming stronger than I was before.

What's really changing is my advantage relative to people who did not have the raid gear I had. When I first hit Outlands, I was blowing things away and soloing group quests. I got to sail almost 6 levels with this particular advantage and only now am I having to treat the quests like everyone else. I think I got good use out of the gear I "worked" for, and I get to do it again with all new content. Farming Naxx every week trying to replace one single item (since I had everything else) was getting old, to put it mildly.

I have no idea if crit will go back to what it once was. But in pve, this will make crit a very valuable stat for its item budget (I have not heard of npcs gaining resilience). The higher the differential between crit and AP, the more valuable the starved stat becomes. The best way to understand this is to imagine extreme examples: If you had a weapon that hit for 1 and no AP, 1% crit would only add one damage over 100 swings. If you had enough ap to hit for 1000, one point of crit would add 1000 damage over 100 swings. If you have to choose between an item with crit and an item with more AP, clearly it depends on what stats you have already. Don't forget that +hit plays a role here too and works very similiarly in terms of scaling (with some complications due to combaty potency, poison procs, that it stops benefitting specials, and so on).

Real world, the difference isn't that extreme of course, but the principle remains. If you're sketchy on the math part of it, there are good DPS calculators around that can help quantify the value of these stats for you at any given time. Look for Pf's excel spreadsheet. This is the best maintained public calculator that I'm aware of.

Has nothing to do with your DPS though.
The higher your AP, the better crit gets.
The higher your Crit, the better AP gets.

e.g. Consider your doing 300dps. With a 80% crit chance. For the sake of argument that would be 1.8*300=540 effective DPS.

Adding 1% crit would make that 543 effective DPS or an increase of 3 DPS.
Adding 28 AP would make that 540 +2*1.8 = 543.6 DPS or an increase of 3.6 DPS.

DPS is roughly speaking AP * Crit.
Assuming you have a fixed budget to spend on your stats (i.e. AP + Crit = fixed number), this equation is maximised when AP = fixedNumber/2 and Crit=fixedNumber/2.

I realize that i did many shortcuts to illustrate my point (e.g. crit does amplifiy weapon damage, AP does not), but generally that is the idea behind "balancing stats".

Did it not cross your mind that Maestroquark might have meant 'your DPS as a final figure representing the sum toto of all effects' rather than the more obtuse 'your DPS as meaning the value of your non-crit average damage' you've just used?

You're just arguing the same point, but you seem to dislike his usage of the term dps.

Yes, it did cross my mind. In fact that was the reason for my reply.
Because crit does not get better the higher your "DPS as a final figure representing the sum toto of all effects" gets.

This behavior does not depend on a mystic DPS figure. Only on the ratio of AP to Crit.
That was my point.

Obviously my point was lost, if you think that my argument was the same.

If we lived in a hypothetical world of equal itemisation, perhaps. At any given point, the better of those two stats to raise is the one you've neglected.
When comparing the dps gains of AP/crit between two points, if the points differ in AP it's crit that offers the best gain and vice versa. This see-sawing balance goes all the way up, the relative value of each totally dependant on their current interplay.
So, in pure theory terms - yes Maestro is wrong.

However.
We don't live in that theoretical world. We live in one where Blizzard itemisation has heavily tilted the AP up and the crit down. The change to crit rating is just the latest effect reinforcing that process. Not since UBRS has it been realistically possible to gear upgrade crit without upgrading AP, and for the most part over favouring AP.
Now in TBC AP values are so high, and even the crit gear adds to them, that no matter where you currently are and what your current balance is - the higher up you are, the better that increase in crit will be compared to the AP one.

Ten expansions down the line, your AP will be in the 100,000s whilst you're still scrabbling for that 1% crit. It's the nature of the stats and itemisation.

That's actually the beauty of crit rating.

*If* Blizzard chose the values properly (and I haven't done enough math to say that they did), X AP vs X crit rating should hold itself to be a very constant ratio, roughly equivalent to the true ratio in damage improvement for a rogue between the two quantities, at least a rogue who didn't neglect one stat or the other. At 60, the itemization ratio between the 2 was pretty solid; 2:1 AP:CR yielding 28:1 AP:crit% is essentially what marginal DPS improvements were showing the relative values to be. I suspect that the trend will hold at 70, where 2:1 AP:CR is suddenly 44:1 AP:crit%; we'll find that at typical rogue levels of AP and crit, a 44:1 ratio makes sense. Yes, AP will be higher, so 1% crit will be more valuable. But at the same time, 1% crit is suddenly more expensive, since it takes more rating to produce a single percent improvement; while your crit% will still be in the 20-35% range, your rating may be in the tens of thousands.

And suicique, crit does get better as your total DPS improves, including independently of AP in some cases; after all, crit scales base weapon damage and base ability damage, neither of which AP effects. A long time ago I derived equations for the nonlinear relationship of crit and AP; the equations certainly didn't tell the whole story of DPS, and didn't even give "correct" DPS answers, but they served to illustrate the point that the "ideal" AP:crit ratio changes as your base AP and crit change.

Actually, I should have added a third value to those equations, producing a surface; the value being itemization cost, we could look for the vector producing best DPS for lowest itemization cost, and aim for that ratio of AP:crit.

Though so far in TBC both crit and ap are not scaling stats at all in a raid setting ;) Since they have effectively "capped" rogues with 'equip' AP+crit rating gear. It seems they want only our base stats to scale with raid buffs... seems this is how they are limiting our potential the most. Look at the tier 4 set, we get a total of 66 agility that is the only stat that scales with raid buffs (aside from stam) everything else is static (attack power and ratings). Tier 5 has 89 agility which is the only buffable stat and the rest are static stats. Puts a bit of a crimp on our "scaling".

Compare that to the druid (sorry best comparison) tier 5 set.
178 strength
128 agility
78 int
41 spirit