I'm asking this question because I currently got Pokemon White ver. since the first day it came out and I was wondering if I need to get Pokemon Black or White 2 for the continuation. I though heard that it's the same game as the previous one and that the only difference is that version 2 gets the zekrom/kyurem fusion or the reshiram/kyurem fusion and that's all. So do u guys think it's worth it for only that legendary? I'm patienlly waiting for Pokemon X & Y to come out and I started playing my Pokemon White version this week on friday just to lvl up some of my legendary's to lvl 100 and such so that I can transfer my Pokemon's from White ver. to either Pokemon X or Y, Once I'm done finishing beating Pokemon X or Y. Oh and I'm getting X btw.
I, and I believe the general consensus, would highly recommend you play Black 2 or White 2. It does continue the story, but more than that it is simply a great game with a good diversity of pokemon to choose from.
Here comes Frogadier And you are not swayed either way--more of a neutral presence.