Final Fantasy 12, Metal Gear Solid 3, GTA:SA, Gradius V, Ace Combat 5, Ratchet 3, Gran Turismo 4. Despite being incredibly sequel heavy, the upcoming PS2 library is still solid with many exclusive titles. I wouldn't write it off yet because the hardware is aging.
I feel pretty much the same way. Personally, I probably wouldn't buy one unless my PS2 screwed up, although I will say the PStwo seems to make me want it for some strange reason. It is just so tiny! For people with an extra $150, getting a PS2 that is only 2.8 cm thick and carrying it around like a book does seem like a cool think to do. I wouldn't be surprised if they get some different colors going as well. Yeah, there is more "powerful" hardware out there for people to buy, but for people who haven't got a PS2 and still want to play GTA:SA, FFXII, MGS3, GT4, etc., the PStwo is something to think about. It may just be a simple redesign, but the PSOne showed how a redesign could still be used to sell console units.