Initial reaction: DS? Huh? That's kinda lame...
Secondary reaction: Oh well... a new Pokemon adventure awaits!
Yeah... I knew Pokemon Black/White's late release would cause some issues for the 3DS, if not with the "Special Edition" (which it now has. ) then at least with Gen VI Pokemon, which won't hit the 3DS for at least a year and a half now. Iwata announcing a 2D Mario for this holiday season seems more important than ever now that a system selling 3DS Pokemon game is still a ways away (not that Pokemon Black/White 2 won't sell 3DS', but not on the scale of Gen VI Pokemon.)
In the end, however... I'm really excited for Black/White 2, regardless of the system it's on. It looks like they're really going above and beyond what has been done in previous "Special Editions", and this will be the first one I'll buy since the original Pokemon Yellow. Can't wait!