EA can still port ME2 to the PS3 without porting the first one. ME2 was made to integrate new players into the story through codex and with character interaction ( Characters explaining Shepard's previous missions and choices during his/her fight with Seren and Sovereign from the first one). Did you honestly think EA and Bioware were only going after the people who bought the first one?
Having played a brand new game without porting a save data from the first ME. PS3 owners can still play the second one and understand the main story of the series.
GamerTag/PSN ID JoshmyersBV (please add me I have 2 friends on Xbox Live)