The universal consensus is that SSF4:AE was a lazy move to make money around my way. It's got 4 new characters, apparently all different types of tweaks for other characters (did Adon's grab range shrink? is Sagat better here than in SSF4?), but ultimately, it feels like the same game right out the box... obviously if you're really into it, you'd find little nuances that indicate difference... but from what I hear, this game is also considerably less balanced than SSF4, so that's when you ask yourself... what's the point?
Fav character of the new 4? Prolly Evil Ryu, but they all still feel real funny to me. Sagat felt like he's supposed to, though, but like I said... this wasn't an in depth play though, just a few rounds.
Overall... I mean, I can't really give this game a fair rating. I played a few rounds or whatever, but ultimately, it still feels the same. You're only going to have to relearn it if you cared that much. Otherwise, I think it's whatever for the most part. Still, $15 for 4 characters probably isn't all that worth it, but it's up to you to decide. I'd prolly get it if I had a PS3, and if you're that deep enough of an SF fan, you probably should get it.
Edit: Here's some more info from my friend, Alejandro:
AE basically gives characters who dont have projectiles a better chance of winning. Case in point: Makoto was low tier but now she can fuck up any body online. As for the characters, evil ryu is strong but low health, Oni is very strong but a little learning curve for him, Yang is balanced to me, and yun is so fucking fast you would think hes broken.
Duke Nukem Forever.... man... I mean, the intro is cute and all, but in the end, it's also a waste of time. Get to the fucking game. It doesn't necessarily take forever to get to it, but I got bored after a while with all the filler. For a FPS, however, I will say that the game is unique (compared to all the bullshit FPS's out there) and I think it's slightly easier than the older Duke Nukem games that I simply just couldn't get into like that. I didn't get to mess with multiplayer though, but for some reason, I think it would be a more fun experience than CoD or whatever else everyone is playing.
I did find the idea that the President in this game wasn't black kinda upsetting. I know it's been 12 years, but fuck you, Obama was elected in '08 and entered office in '09. This is '11. Step up.
So it's probably not a perfect game, but my guess is that it will be a fun experience, littered with "12 years" [of] jokes that are probably going to get "old" quick. This is yet another game I can't necessarily outright recommend, but you could try it and see if it's for you.