Yes, but it would depend on a few things:
One of those things is the PSP which has even been beating DS(i) the last couple of weeks. One of the big exclusives coming to Wii is Monster Hunter G. Isn't this game also no longer an exclusive on Wii but going to be on PSP as well?
If the PS3 gets games like FFXIII and GT5 in Japan this year while the PSP gets a lot of versions of games that were originally supposed to be third-party Wii exclusives (like the 360 getting FFXIII in the West) as well, and Nintendo just has to get by on their own series (With no Zelda or Mario this year), then it is possible the PS3 could outsell Wii in Japan this year.
Heavens to Murgatoids.







