McGuire was given a ten year deal when NBC renewed the rights (which also stole him from TSN). I don't think it will be anyone from a game coverage. Most likely an insider who can contribute to their news shows.
Off the wall prediction: Chris Cuthbert to FOX to cover NFL games.
I would be so disappointed if Cuthbert ever left Canada. He's been one of the best play-by-play announcers in the country for over twenty-five years. One of the voices of Hockey Night in Canada in the 1980s, 1990s, and early 2000s, voice of the NHL on TSN since the lockout, CTV's primary Olympic hockey play-by-play man, and the voice of the CFL for the past decade.
With the real possibility that CBC will lose the NHL rights soon and TSN has locked up the CFL with a new deal. CBC Sports would be reduced to the Winter Olympics and World Cup for 2014 but after that all they have is the Summer 2016 Games.
With the talent at TSN and Sportsnet likely not going on anywhere he would be smart to join FS1 and work his way up. Who knows where he could be in 5 years as part of the Fox Sports family.