I didn't play my old PS1 games on the PS2 anywhere near as much as I expected, then again it was never really a selling point for me, rather a nice extra. I've got room for an extra old console afterall.
The PS3, however, I believe is region free for games, and I assume this includes PS1 and PS2 games as well? If so, it would be great to get games that were never released in my region, providing they are still available to buy, of course.