PS360 are effectively one system, developement will begin with both systems in mind, porting across is less then 5% of developement costs and if you begin with both systems in mind on a multiplat engine there are no porting costs, albeit it may take slightly longer.
If we're going to look at this from a dev's point of view you really need to combine the PS360 sales, because they are for all intents and purposes one market now. It'd be equally fair to compare Wii and PS2, albeit we know that the PS2 market is becoming less and less relevent.
If anyone could be arsed do a Wii vs PS360 million sellers list... sounds like too much effort lol.







