Ah, I missed the exclusivity part.
PS3/XB360 was when happened a strong shift in the concept of multiplatform development.
In the distant past multi-platform games were developed as different SKUs usually by different teams or companies.
Instead today multiplatform development is intended as a project that targets multiple platforms.
I'd like to add that on PS2 third-party games gained even more prominence than on PS1.
Even multiplatform third-party games tended to sell far more on PS2 than on Xbox or GC because PS2 was perceived by consumers as the de facto TV console to own to play third-party games.
GTA SA, which became PS2 top selling game in US, was also available on Xbox (though PS2 had 8 months time exclusivity).
The landside victory of the PS2 version over the Xbox version was in part due to the time excludivity but also because the 3D GTA series grew in popularity on PS2 before landing on Xbox and PS2 had a massive userbase advantage.
Third-party games available on day one on PS2 and Xbox tended to sell more on PS2 anyway.