Tatsunoko VS Capcom: Ultimate All-Stars. You know you're going to buy it. I have the Japanese version, and I'm still buying this.
I think Amazon is the way to go if you haven't pre-ordered this fighter already. Their price of $46.99 is pretty good already, but they're giving away a bonus $10 in credit which you can use toward another game. I'd hold on to the $10 credit, as Q1 2010 is already looking pretty crazy.
The site is accepting preorders for this January 26th release.