[quote name='Untamed Sorrow']I guess so, but that's just lazy on their behalf, I would've gladly jumped on this for 360, also are these direct ports of the PS2 versions ? If so due to hardware limitations they were inferior to the Xbox versions. Especially the 1st one with smaller areas and "lighting" issues....but it did have a bonus stage.[/QUOTE]
Wikipedia page for Splinter Cell mentions that they were ported from the PC versions.
"A PlayStation 3 version was announced to be part of the Splinter Cell Trilogy which was released in September 2011 as part of Sony's Classics HD series. It was revealed on the PlayStation Blog, that it would be ported from the PC version, because it had more details and more content than the PS2 version."