The company did say last month that some popular PSX games would never be available via PSN, simply because they are too complicated to port or are too buggy.
Sony removed all PS2 backwards compatibility from PlayStation 3 consoles early on, claiming it would lower costs which would then be passed on to the consumer.
Regardless, there will certainly be buyers for blockbuster games like God of War and Grand Theft Auto, especially if available on the upcoming Sony NGP (PSP 2).
Hope they put GTA san andreas in there with full HD. I will definitely buy that.