Wasn't the GC version of Soul Calibur 2 (at least in America) a higher seller than the PS2 version just because it included Link? Even with a huge userbase difference (much more than the PS3 and 360 difference), the GC version still came out on top.
Now we have one version with Darth Vader and one with Yoda. Who do you think is the massively superior character here? Due to the popularity of the series on Sony consoles, it's very likely that PS3 and 360 sales for the game in America will be close. With that in mind, the PS3 version will decimate the 360 version in PAL and Japan, there's no question of that.
The situation is pretty similar to Devil May Cry 4, so you'd have to have a pretty small amount of knowledge about the market to claim the 360 version will sell better.
