Just about everything can be an anti air, there's almost too many options. The timing for the "alpha counter" that cigs mentioned is a little strange for my liking, haven't been able to make it happen when I want it to except for one glorious time when it saved me.
It definitely has the poke mentality right now though, jab pokes will stop SO MANY MOVES from coming out and also they are very easy to hit confirm. That's something else I could never really get in most other fighters, but it seems the window of opportunity is much bigger in this game. That's why I don't understand too much button mashing in this game, the game seems to give you a lot of time during a combo to trigger the next move and link it into whatever.
I was playing yesterday with a random guy I met in SSF4 and he was complaining about how he couldn't get a grasp on the combo and launcher system (lol really?). I told him to just try the basic lp mp hp hp, that he could do it with kicks and a couple other quick things, and all of a sudden he was as good as most people I've seen playing.
So it really seems like the quick poke combos into launcher and the high/low combos that a lot of the Tekken people have are the main things that are working right now. It's nice because it makes it fairly easy for most people to jump in and play, given that every single character in the game shares a couple of basic combos that lead to huge damage.