To make things more stressful, I might give the warlock less HP: maybe even 6, like the wizard, so the warlock has an interesting decision to make about whether to stand next to an enemy.

So jealous.

http://www.doityourself.com/stry/make-a-diy-dimmer-for-your-christmas-lights

As an addendum, there is a thunderstorm coming up in the game, and I was just looking into light controllers. How cool would it be to program the lighting to flicker in time to the thunder crashes of an audio track? Sadly, it is more money and work than I am currently willing to cough up. (Especially when it will only see use in one game session . . .)

Evasive flutter is also a big power. When most people shift, they are stuck moving only one. This is slightly worse than the assassin’s shadow step power in one way but much better than that in two ways. It’s worse in that all movement after the first square potentially provokes. But it’s better in that it moves 25% farther and you can go anywhere. The assassin needs to start and end next to another person, which is a significant limitation. Personally I’d remove it and let a feat get you an encounter version, and a paragon feat to make it at-will.

Multidexterity: As I remember, they used the hands on their wings on the ground and the hands on their feet in the air. They would rarely use both sets. From your wording, it sounds like you wanted to keep that, but it’s unclear how your words would translate into rules. If they have a free hand, what if they use it to grab something? I would do it like this:

Multidexterity: Aarakocra use their wing-hands when on the ground and their feet when flying. They may transfer one item between their hands and their feet as a free action when taking off or landing. When on the ground, they may use one foot as an additional hand, but they are slowed and grant combat advantage while doing do. They may use their beak to make unarmed attacks and to hold an item of no more than five pounds, but cannot manipulate that item (including using an implement). They cannot speak intelligibly when holding an item in their beak.

@DeadGod:
Staunch survivor is a specific limited benefit. I don’t see it as an issue.
4e reduced the options to learn new languages, but also reduced the number of languages. Bringing in a new language makes it hard for non-int based characters to learn it.

I thought flight was a powerful enough feature that I didn’t feel the need to include something like “Staunch Survivor” as I feel the bird-men don’t have any reason to be more hearty than any other desert-dwelling race.

Evasive flutter is interesting, but the solution I came up with was a per-encounter power that simulated their diving attack. (I think it was a react that triggered off of a successful charge attack and added +1d8 damage.)

I also included some racial feats to add to their natural abilities, but I can’t recall any of them now.

Two comments on your writeup:

#1. Languages: Why is this not “common and Aarakocran”?

#2. Multi-dexterity: I feel like Aarakocra do not possess true thumbs, and thus must actually use their foot/beak combo to effectively manipulate things. I feel like this limitation would render your “third hand” idea moot. (For instance, you probably shouldn’t see them holding a weapon, an implement, and a shield.)