On the PC, you can get high rez and use FSAA and all, but on the PS2 (and other consoles), there's some depth of field effects that help it feel more immersive, and you don't get them on the PC.
Ubisoft has released a patch for Splinter Cell: Conviction, which should auto-load for you considering you have to be online at all times to play the thing. Updates include: Added DLC support; ...