The Euro PSN update today has some nice demos for you. WET, DiRT 2, Mini Ninjas, and IL2 Sturmovik: Birds Of Prey.
Add-ons consist of Andy Dick for the game Pain, a Street Fighter II themed table for Zen Pinball and the usual Rock Band and Guitar Hero stuff.
PSP users can get Wild Arms XF, Riviera, Warriors Orochi, and demos for Dissidia Final Fantasy and Colin McRae Rally 2005.
The full thing is over on the EU PS Blog. Go have a look.