Like I mentioned earlier, I can easily see Bioware implementing a short, interactive summary of the events that took place in the first game, prior to starting ME 2 on the PS3. It could possibly be presented as a flashback, allowing you to decide how the flashback went (what choices you made in Feros, Noveria, Virmire, etc.), so that PS3 players not only get brought up to speed with what went down in the first game, but also gives them the chance to manipulate some of the major parts in the story (i.e., who you saved, who you killed, who you romanced, etc.) so that their experience in ME 2 is similar to that on the 360 and PC versions.
And that's merely one way that Bioware could make ME 2 easier for PS3 players to get into; I'm sure there are far more creative ways that this could be done. At the end of the day, we don't really know exactly what Bioware is going to include in the PS3 version of ME2, but it's probably safe to say that they are going to include content that will try it's best at giving PS3 players a similar experience without having to play the first game.
Even then, playing the first game isn't really as important as some people are trying to make it out to be. I personally only have one character imported from the first game, with the majority of my other "Shepards" created from scratch in the second game (I'm not a big fan of the first game's combat, so I just can't force myself to play the first ME again just to import a new character).