@ mrstickball
The XBox 360 userbase is currently larger, also it seems quite a few PS3 owners also own a XBox 360 and may already have bought the XBox 360 version.
I think at least in North America there's a lot of confusion if the PS3 is better than the XBox 360 version or not. Early report claimed the XBox 360 version to be graphically superior likewise does a Gamespot article, but comparison pictures and videos show the PS3 is visually the better version and the VES rewarded the PS3 team with the 'Outstanding Real Time Visuals in a Video Game award' for 2006. I also am of the opinion that the PS3 version is graphically the better version, but the added first perspective option for the PS3 makes it easier to say which version is better. The PS3 version suffers somewhat from loading times, which could have easily been reduced if taking more advantage from the PS3's default configuration. I guess EA rushed the game a bit to meet launch day, final PS3 dev kits were out rather late only a few months before the official launch.
According to insiders the PS3 is easier to develop for than the PS2, also some claim that with regard to the PS3 it will be easier to tap into the PS3's hardware potential if comparised to the XBox 360, which also still has quite a bit of untapped potential.
Further I agree completely with you, I think Sony is going to help push their exclusives to very high levels (for instance Killzone), so that multi-platform developers would look incompetent to consumers if they aren't optimising their games well enough for the system. I think with regard to the average PS3 consumer graphics, AI, physics, the scale of environements, etc all matter a whole lot more than for the lower-end consumer who may not own a good HDTV and audio equipment to enough the PS3 to its full potential anywhow. (the PS3 still look a more impressive even on a 480p TV compared to non-high def consoles though) So I think and hope multi-platform game companies cannot afford not to learn the way of the PS3 (multithreading game engines).