When Locke asks Ben "Who is your man on the boat" Ben replies something like "You may want to sit down for this." We the audience, of course, do not get to hear who it is.
Spoiler: It's Michael.
...or at least that seems like the obvious "surprise" - which at first pissed me off. It's so obvious it's a little bit painful. That being the case, maybe the writers are playing off that to actually surprise us with a character that's not a total waste of screen time... but i doubt it.
I hate Michael. As a character, he is a selfish, obnoxious, stereotypical piece of crap, and as an actor, he's a dreadful twat. I expect that all he'll say this season once he's back is "WWWAAAAAALLLLLLTTTTTT!!!!" hundreds of times.
But this got me thinking, maybe "resurrecting" Michael's character is actually a really good thing. When his character was finally gone, i was really relieved, but a little sad that he "got off the island" instead of "got shot in the face."
Maybe now we'll get to see him die. That'd be worth bringing him back. ...but my gut instinct is that the writers will try and put some redemption bit in and use him for a couple of lame flashback episodes filling us in with what happened on the freighter (filler episodes) and trying to cast Michael as a good guy.