The PS2 Classics brand is both good and bad. It's fantastic to have access to these games (not quite at the price they charge, but still), but as soon as they release you can almost discount the possibility of it ever becoming a HD Classic, with upgraded visuals and trophy support. Still, if I had to choose between not getting a game digitally and getting it without any bells and whistles, I know which I'd choose.
The other good thing about the PS2 Classics brand is how rapidly it's expanding, and it's soon going expand quite a bit more. Deus Ex has been rated for release on PS3 in Europe and, presumably, that means it's coming to the PlayStation Store. Now that it's rated, it'd be nice to think that release is just around the corner, although we've learnt from experience that that's not always the case.
It also seems that people are advising against buying the PS2 port, although for those without the option of playing on the PC, this is a great opportunity to find out what happens after Human Revolution.