Paget Brewster and AJ Cook returning to Criminal Minds. . .?

That's a good question. I think Hotch knows Prentiss is alive, I think that's what JJ told him when they were alone. I think that Doyle will be captured making it safe for Prentiss to come back. As for her relationship with the team, there may be some anger and sore feelings for a few episodes, if they play their cards right we can expect some major tension and drama especially from one character in particular... Garcia.