Gamestation sell used PS2s. I'd be surprised if you couldn't buy first-hand PS2s in high street stores, though, as the PS2 was very recently still outselling the PS3 - possibly still is?
Lots of games still coming out on PS2 - Persona 3: FES just came out a few weeks ago (in the US, still not had its European release), not to mention most multi-format titles like... umm... Marvel: Ultimate Alliance, Iron Man, Hulk. Hmmm. Marvel titles, I guess.
The PS2 still has many new releases, and I'm almost 100% certain that one or two of them have nothing to do with Marvel.