According to Ubisoft, the three games in the Splinter Cell Trilogy are based on their PC iterations instead of the not-as-nice PS2 versions. This decision was an easy one for the team, according to a post PR Coordinator Alex Monney left on the PlayStation blog:
When we started this project, one of our main goals was to provide the players with the best possible content. Hence we decided to port the game from the PC version which had more content and detail compared to the PlayStation 2 version.
While none of the games will feature multiplayer, they will all feature HD, stereoscopic 3D and trophies. The three games will be available in a bundle and separately on PSN and on a disc in stores. They’ll be available in June.