For most AoE, like Arcane Explosion and such, it's enemies x yds from the character will be affected in all directions, but what about things that seem to affect the ground around the player, like consecration? I was in the arena, fighting a paladin. I'm a rogue, so, wanting to remain stealthed, I go up on top of the bridge to drop down and hit the paladin before hitting the consecration on the ground.

I spam my cheapshot button on the way down, but get destealthed before getting in range to hit the paladin.

So... is there an amount of space above the ground that is also affected, or was it just latency to make me unable to land my hit before hitting the ground? (this being the test server, latency could well be the cause)

Well, just yesterday I jumped off that bridge in the arena and spammed ae in the air cause I was hunting a shaman with 2% health. None of the ae hit him mid air.. Could be lag of course but it felt strange.

Not to mention flare. The flare area is at least twice the size of what you see on the ground. Can't tell you how many times my druid has been pulled out of stealth even though I was 5-10 yards away from the flare gfx.

It's an instant, so I can't imagine why not... it's something that didn't cross my mind, though :P I'm pretty sure you can, though.
It's intended, I think, that the flare graphic doesn't cover it's entire zone... if you ever cast the flare yourself, you'll see the target circle of the flare is about 2-3yds wider than the graphic that shows up after throwing it out.

It's also possible that CS, which requires a target, forces you to the same elevation as the target. If that's the case, maybe the game moves you before executing the CS and not after. The same wouldn't happen with AE, holy nova, etc, or with an instant that's meant to be ranged. Although I don't know how many times I've seen a hunter do Arcane Shot or Scatter Shot while falling.

Just duel someone mount up and see how high you can fly with still taking damage.

Thottbot lists Concecrate as using the same effect as Blizzard, Rain of Fire, and Volley.
http://thottbot.com/?sp=20924

I'm not sure of anyone has done testing to see the vertical range of this effect though, or of the "spherical" AOE's like Arcane Explosion or Holy Nova. All of these effects have a "radius" parameter, but the game could check them as a sphere, a cylinder, or a truncated cylinder. I wouldn't rely on the graphics since there is not necessarily any correlation.


Edit: I am reminded of back in Diablo 2, when players were trying to figure out the ranges of various auras. They did some testing and found that the aura-application zone was not even remotely circular. Blizzard corrected the aura math after that...
http://www.lurkerlounge.com/content/view/826/120/

I'm going to guess you didn't spam fast enough. To give you a rough idea of how fast you can spam versus how fast you are probably spamming:

I used to have one keybind on cheap shot and used to spam that when I needed to get a really fast cheap shot on someone (i.e. before being seen and AE'd, or on a rogue/druid in stealth). I timed my apm (basically, how many "clicks" per minute) at about 200-250.

On the advice of a friend of mine, who happens to be one of the best pvp rogues I've ever played with, I bound 3 buttons to cheap shot, on her theory that spamming 3 buttons at the same time gives a far greater apm and leads to faster cheap shots. My apm went up to 400+.

I guess what I'm saying is: no matter how improbable you think it is that you can hit the cheap shot button too late, you can always make your cheap shots faster, and you may have just missed the tiny window where the game allows you cheap shot the pally without taking ae damage.

This is all theory of course, it could be that consecration has some vertical range. And by the way, I'm about 95% sure that I have cheap shotted people in midair before... the 5% just being that I can't completely account for lag making it appear that way.

Midair meaning falling or jumping? Maybe everyone is already talking about falling but I did see one post mention jumping around. I don't think jumping produces a real elevation difference on the server side.

I've used Blink while jumping and it works normally. Blink while falling from one elevation to another resets me to the top. My point in this is that I don't think consecrate is treated as a cylinder, I think terrain is made into platforms and as long as you're on the same platform as the caster, you get the damage. And I'm guessing that melee instants force you to the same platform as your target if you're between two platforms.

My rogue got stuck at 35 and then abandoned. The only experience I have with falling melee instants is Charge which is kind of half melee half ranged.

Well, I was talking about falling. I'm 95% sure I cheapshotted someone in midair while falling from the stables entrance to the mine in AB.

Um, what? How would people jump onto objects/over things/around terrain/etc then?

As a couple of examples to go with this:

See: Overrated AQ hax. Hunter Stairway to Heaven hack on PTR.

The former is obvious, the second one is just hilarious. A few PTRs ago, some Hunters figured out that if you replaced the Trap model with a model of a Staircase, your client actually thinks that it's a staircase. Thus you could essentially walk into thin-air (that's what everyone else sees) and when objects beneath you despawn (BRD keg anyone?), you maintain elevation. Thus you could lay another trap and just keep on walking in mid-air.