Gameswank have provided a very good upscaling comparison for the PS3, using roll-over for the images. This is the definitive upscaling comparison.
With the PS3 1.80 firmware update, one long awaited feature has finally arrived: the ability to upscale PS1, PS2 games, and DVD's. This now places the PS3 right at the top of HD players. With this feature nothing is holding back the PS3 from being the ultimate Blu-ray player; but also from making our much loved classic games look better than ever before.
Follow the link for the images, the results are quite dramatic.