It's been in development for two and a half years. Originally as a lobby for a PS2 multiplayer game, then as a possible PS2 online service. When they realised that they couldn't do anything that they wanted to on the PS2 because of lack of power, they put it on the PS3 instead.

On the exclusives front, there are some crackers coming out this year, and early next year:

Lair
Heavenly Sword
FFXIII and Versus
MGS4
Little Big Planet

Not to mention R:FoM and Motorstorm, which are out already.

To be honest, exclusives aren't as desirable to developers as they were last generation. The best way to make money, and build up a fan base, is to release multiplatform games, especially at this stage when the PS3 is still a bit shaky - if you were a third party developer, would you risk a multimillion pound/dollar game on a system that can still 'fail'? The words on the street seem to be "cover your bases".