I think there are a few paths to a Rose Bowl assuming no bad loss for Michigan or OSU:
-Finish with 2 or more losses in regular season but win B10 Championship game
-Finish with 1 loss in regular season (win out), lose to OSU in B10 Championship game (I think there are very good odds we would finish ranked above Michigan due to beating them in Ann Arbor)
-Win out including @Michigan and vMichigan or vOSU and have the misfortune of TCU and Clemson going undefeated along with at least 2 other one loss SEC teams or Pac10 teams (i.e. no B10 team makes the CFP). This would make for the greatest Illini football season in my lifetime and yet would also be the most heartbreaking (even more than Fumblegate against Michigan and losing in OT to #2 OSU in 2002)
That said, I agree in enjoying this season and each game for what it is. It has been beyond amazing and no matter what happens this will be a season I always look back on fondly (That said, winning in Ann Arbor is something that'll bring me a lifetime of joy, so please make it happen, guys)