That statement isn't valid anymore (for skull bash in particular), go look through logs since last night. It was indeed true that Skull Bash could actually miss and the interrupt would still go through - doesn't appear to be the case anymore.

The interrupt can never miss, the skull bash effect can miss.

You may have the ability blocked/avoided/miss but the interrupt portion will never fail to occur on something which is possible to interrupt.

No, the interrupt itself can miss now. I tested it today myself and you can look through logs for other confirmation if you need.

With the normalization of gear in cata, primary stats are going to be the same on all pieces of gear for a given ilvl and slot. That being said if you are just starting heroic 5mans and have just made the avg ilvl limit you will have to gem/enchant a bit of stam, but as you get more 346's and the epics from rep, you can swap out for agi.

In fully 346 gear with 3 - 5 epics from rep/crafting you should be at aprox 150-160k fully buffed without gemming or enchanting for stam. You can always use helm/shoulder arcanums (and bracer enchants if you are LW) to even out your HP.

What about our taunt? Does it still have 100% hit if we're at 0 Hit ?

Yes, taunt still has 100% hit.

•Skull Bash no longer interrupts the target if it fails to land successfully. from blue post today;

Does this now mean, especially for 10-man's, hit has moved up in our stat priority? Certain fights almost require the tank to be able to interrupt in a rotation on the boss, raid set-up effecting this obviously).

Other tanks don't do this either. In particular warriors complain all the time about shield bash missing.

I could be wrong, but I suspect that shield bash can't be parried or dodged either, meaning that expertise doesn't affect it. That makes it easier to hit the cap for it. Mostly, I suspect that interrupts for tanks are going to be a nice to have thing but not a required deal, and that DPS are going to be the ones responsible for interrupting crucial abilities as they have the hit for it.

That I believe seems to be the intention: Blizzard is trying to make it clear that interrupting is solely a DPS task. It seems a shame that they gave all tanking classes a short-cooldown interrupt if the interrupt is unreliable without making large survivability sacrifices (at least in this tier). We will have more gear itemization points in later tiers, so perhaps we will see tanks capping these stats and helping with interrupts then, but for now it seems tanks helping with an interrupt rotation is no more.

Don't count on it changing in subsequent tiers - we'll need more hit and expertise to reach 0% miss at that point.

What he means is that Blizzard has stated that you'll need more hit/exp against later tier bosses. No details have been made public as far as I know though so how that will affect tanks aiming to hit cap I don't know.