I agree with you, most XBox 360 owners are FPS fans (due to games like Call of Duty, BioShock and Gears), so releasing a game like Halo 3 will do very well amongst its userbase as will other 3D shooters like Mass Effect. Halo 1 and Halo 2 were the original XBox' most important games, so I think it's not much of a surprise. The Wii has a much larger percentage of yound kids and females playing, while PS3 and XBox 360 is preferred by older teen and mature males according to surveys.
I do applaud the approach of game diversity though, games like Singstar and Ratchet & Clank can be enjoyed by the whole family. On the PS3 there's still a lot to keep the hardcore FPS fan satisfied with good 3D shooters like Warhawk, Resistance, Unreal Tournament 3 and Call of Duty 4. I think having a large game diversity is good for the long run, eventually there will be a slimline PS3 for kids to afford and there will be a nice selection of games to choose from.
Killzone 2 (and of course Metal Gear Solid 4 and later Resistance 2) I think will be very important for the PS3 to be more viewed as the ultimate shooter console, I think that in people's eyes offering the best is more important than the amount of games offered within the gerne (quality above quantity). Personally I applaud the addition of light hearted games like Snakeball and LittleBigPlanet to it's games library as I'm not the type of guy who plays 3D shooters all day long and like the ability to play some game with my girlfriend (she hates FPS games, she loves Motorstorm, R&C, Super Stardust HD, Super Ruba Dub, Fl0w though, of the PS2 games she likes are Ape Escape 2 & 3, but for instance she doesn't feel like playing God of War games although see likes to watch me playing these, unlike FPS games, I guess too hectic/disorientating to watch).







