In addition to the new characters, and online matchmaking, Tatsunoko Vs Capcom: Ultimate All-Stars also got an in-depth rebalancing.  It ranges over everything, from cleaning up some pesky infinites, to character buffs, to new launcher properties, and more. 

While I hope to be sharing some more specifics on what has changed soon, in the meantime, the Shoryuken hardcore have put together a great primer on what's changed from TvC: Cross-Generation of Heroes to TvC: Ultimate All-Stars.  Check it out here.  

And in closing, just a random video of some great LA players (Il.nd and RoyalFlush) going at it on the arcade Tatsunoko Vs Capcom--the game that started the wave of excitement that eventually brought us the TvC: Ultimate All-Stars we'll see soon.  <3 OG TvC too :)