You might already have a 360.
The point still stands. If you already have an XBox 360, there's even less of a reason to get a PS3, when you can get both good 360 games and 8 mediocre ones for the same price as the PS3.Besides, you already know the only games worth getting for the PS3 is going to be GTA4 (and its derivatives) - this time around, you can get it for Microsofts console as well.
it'll take a few years for the games to be significantly better than the 360 one's
If by "few years" you mean "forever" then sure.