One, but it has to be one exclusive that I really want. A Tales game would most likely do it, I already got a 360 just for Vesperia and a PSP for Eternia. So which platform the next game in the series ends up on will likely swing my choice of next gen console. Not planning on getting any of the next gen consoles at launch though, I think it'll probably be a while before there are any games I'm interested in released anyway.
I have no specific number in mind with regards to games either at launch or coming to the console. It is going to be a combination of games and features that will ultimately determine my purchasing decision.
the bitter truth is that in the grand scheme of things, the average piece of junk is probably more meaningful than our criticism designating it so. ~ Anton Ego