In an interview with Slice of Scifi Paul McGann was asked about the rumors of a reuinon of all the living Doctors for this year’s Children in Need. He said:
"It’s highly unlikely, because since I walked off that set in 1996, no one’s ever called me, I’ve never met these people, I’ve never been down to Cardiff and met what’s his face, Russell T Davies (who masterminded Doctor Who’s revival),” McGann says.
Okay Paul here is a little tip, if you would like reprise a role it is a good idea not to call the Producer “what’s his face”. May be you have a shot now that “what’s his face” is not the producer any longer. Don’t call Steven Moffat “what’s his face” and you may have a shot.:o
I would great to see the transition from McGann to Eccleston, as well as more background on the Time War, but yeah, talking like that probably won’t help that happen. 
Never let it be said the bounds that an actor’s ego has. Yo STUPID! MAKE NICE NICE AND YA MIGHT GET A PAYCHECK!
This is all weird, since he’s done 50ish original audios for Big Finish Productions as the 8th doctor and has said in interviews (at the end of those CD’s) that he’d love to do it again.