User blog comment:LazyCloud/ME1 was for RPG fans, ME2 was for shooter fans, what's ME3 for?/@comment-72.84.7.84-20100529150012

I'm guessing it will be a mix of squad members from ME1 & 2 plus new recruits in 3. If they keep the number of squad mates at least the same from ME2, you'll need about 12 people. Here's a list of all the ME1 & 2 squad mates and why or why not, in my opinion they stay with you (or rejoin) or leave the Normandy (This is assuming they're all alive):

ME1 Characters: I'm sure Tali and Garrus will stay with you, they don't have a good reason for leaving, especially if you got Tali exiled. Liara might join you again, but I'm guessing you'll have to help her kill the Shadow Broker first. Wrex probably will stay on Tuchanka since he's a clan leader. Ashley/Kaiden could join again since you're not with Cerberus anymore.

ME2 Characters: Legion I'm guessing he leaves to do his Geth thing. We'll probably see him, or others like him, again though. Grunt probably goes to Tuchanka since his clan needs him. Jack probably leaves too to kill all the people who f*cked with her. Jacob/Miranda don't have a reason to leave so I guess they probably stay. Zaeed/Kasumi probably don't appear in ME3 for 2 reasons: 1) They're DLC and 2) The mission was was a "job" for them since they were the only ones to get paid. Mordin I'm guessing leaves. Genophage work? Thane, sadly, will probably be dead sometime during the events of ME3, due to his Kepral's Syndrome. There should definitely be a funeral scene for him. He was awesome. Samara planned on leaving after helping Shepard with his/her mission, so I'm sure she won't be in the squad. Morinth is a sex addict so she'll probably be gone too.

So yeah, that's only 6 people (in my opinion) at most who stay (or come back) in your squad: Garrus, Tali, Kaidan/Ashley, Liara, Miranda, Jacob. So yeah, we'll be needing to recruit again.

And as long as the Normandy 2 doesn't blow up or something, I think all ME2 crew stay the same, Joker, Doctor Chakwas, Kelly Chambers, EDI, etc.