Well, it's finally come out.  Grabbed my collectors box (which I guess was worth it.. shrug) and popped it in.

First off, the game has a massive amount of unlockables.  It starts you with 12 characters, and leaves you to unlock the other 14 or so throughout arcade mode.  Arcade mode, or basically story mode (I dunno, do fighters have story modes?) starts off with an anime cutscene of what your character is fighting for etc etc, and ends with another cutscene after fighting the main boss.  The main boss was pretty badass.  His moves are a combination of several of the fighters in the game, ie, he can throw sonic booms and do Ryu's uppercut.  He's actually pretty tough for a boss, but no where near how insane M. Bison was back on Street Fighter II. 

The game also has challenge mode.  Which includes, Time Attack, Survival, and like a Combo/Button Input challenge for each character.  All of these things will unlock you either alternate colors for every character, or titles for your online persona.  This is actually something I thought was fairly neat about Street Fighter IV.  You can get titles whenever you do various things, for instance, when you beat Chun-Li's combo challenge you can get, "Heavenly Kicks" or "Double Hair Buns".  It's a neat feature even if it is just cosmetic.  There's also countless amounts of icons you can decorate your SFIV persona with. 

In terms of online play, which is a massive part of fighting games on the xbox, everything seems to run smooth.  Played a bunch of games with a friend of mine in California (I'm in Connecticut) and we saw no lag.  However, if you want to get competitive I'd suggest picking up a Street Fighter Fightpad made by MadCatz.  The Xbox 360 dpad is just freaking terrible for anything, especially precise motions.  And I couldn't even really use the control stick too much… So I'll have to grab a fightpad at some point. 

All in all, I absolutely recommend this game.  If you hated SFIII, this is WAY different and will not let you down.  I love everything about this game so far except the new characters they added.  I feel they're gimmicky and lame, but i'm sure i'll learn to love em =)

Yeah as far as characters goes, it has every single character from Street Fighter: The New Challengers, except for Dee Jay and T. Hawk.  There's also a few characters from the Alpha series tossed in there too.  However, I've heard that Capcom is already planning on making a revision to the arcade cabinet modifying various things and adding in T. Hawk and Dee Jay, so whether the console gets that or not has not been said.  I really could care less about T.Hawk but it'd be great to see Dee Jay again.

Yeah, its dumb.  But every game gets milked.  And at least the costumes are just unlockable 8KB keys that are already on the disc.  They're brand new, and some are kinda cool.  Like Zangief has a costume that makes him look like Haggar from Final Fight.