EDIT: A friend of mine pointed out that Massachusetts joins the MAC next season.
My speculation is based on Michigan's current schedule, the "agreement" that Big Ten teams play MAC teams, and based on the current MAC teams schedules. I tried looking everywhere I could think of to find the MAC conference schedules for 2012 and beyond, with no success.
(1) With that said, let's start with Michigan's schedule for 2012:
S1: vs. Alabama; S8: Air Force; S15: OPEN; S22: @ Notre Dame; S29: OPEN
O6: @ Purdue*; O13: Illinois*; O20: Michigan St*; O27: @ Nebraska*
N3: @ Minnesota*; N10: Northwestern*; N17: Iowa*; N24: @ Ohio*
(2) Teams in the MAC that currently have a full non-conference schedule (with their opponents in parenthesis):
Ball State (@ Clemson, @ Indiana, USF, @ Army)
Bowling Green (@ Florida, Idaho, @ Virginia Tech, Rhode Island)
Buffalo (@ Georgia, Morgan St, @ Connecticut, Pittsburgh)
Kent State (Towson, @ Kentucky, @ Rutgers, @ Army)
Miami (OH) (@ Ohio, @ Boise St, Missouri, Cincinnati)
Northern Illinois (Iowa, UT Martin, @ Army, Kansas)
Ohio University (@ Penn St, New Mexico St, @ Marshall, Norfolk St)
Temple (Villanova, Maryland, @ Penn St, @ Army)
Western Michigan (@ Illinois, Eastern Illinois, @ Minnesota, Connecticut)
(3) That leaves us with:
Akron, Central Michigan, Eastern Michigan, Massachusetts, Toledo.
I tend to think playing EMU in 2012 is very unlikely. EMU and Michigan have what appears to be a common open date on September 29, but the two will have met just this year. I just don't see this happening. Further, EMU is playing at Purdue and at Michigan St. Down to Akron, Central Michigan, Massachusetts, and Toledo.
Believe it or not, Michigan and Central Michigan have not met since 2006. With that said, I highly doubt they will meet in 2012, but 2013 or 2014 are possibilities. CMU faces both Michigan State and Iowa in 2012; facing three Big Ten teams in the same season is highly unlikely. Down to Akron and Toledo.
The Minutemen and Wolverines met last year in the Big House. UMass has Connecticut on the road on August 30 and faces Indiana at home on September 8. September 15 and 29 appear to both be open for a meeting between the two. However, given the recent meeting, I don't see this one happening.
Neither Akron nor Toledo have any Big Ten teams listed on their non-conference schedule in 2012. Toledo is @ Arizona, @ Wyoming and home to Coastal Carolina on the week of September 1, September 8, and September 22, respectively. That would leave September 15 or September 22 as possible dates for a meeting in Ann Arbor. My hunch is that Toledo schedules another home game for 2012. I also believe AD Brandon would not want to set up Coach Hoke with another tough non-conference opponent in 2012. That leaves . . .
Akron and Michigan have not played before from what I can remember. Akron only has one non-conference opponent scheduled for 2012, UCF, and no date is set for the game. Akron is not a good team, would give Michigan an easy game, and would provide the Wolverines with a MAC opponent.
Thoughts on who the fourth non-conference opponent in 2012 could be?