Not at all. You're getting more fighters to choose from, better presentation, deeper career mode, and more moves/gameplay options in the octagon.
This isn't like snagging Mass Effect 2 without playing the first one by any means.
Also hit up the same stores listed above. Not much pickings left. The typical Far Cry 2, Mass Effect, Bioshock, etc. Saw a copy of Rock Band 2 for the 360 at the Durango store mentioned. Guess we missed the boat :cry: