discuss the subject on the gambit thread (http://www.killermovies.com/forums/showthread.php?s=&threadid=20538)
As far as I nkow there wasn't much to it, the X-men dumped him in the middle of that arctic, it seems he helped orchestrate the whole mutant massacre by hand picking all the Marauders for sinister.
I would have had him be made guardian of leech that would have been a poetic penance. Has anyone else ever wondered if Gambit is actually the child of sinister and a human? Some things are just wierdly common between them, plus they seem to be connected in all realities, in Mutant X he raised the would-be Rachel Summers after he was ordered by Sinister to kill her.