I think the Little Caesar Pizza Bowl is a lock for NIU. I believe they ( the LCPB) would not choose Ohio over NIU because of the poor attendance last year. Last years Ohio vs Marshall game in Detroit had the lowest ever attendance for that event.
Now as far as opponents... If Wisconsin and Ohio St/Michigan St win out I will assume that both will go to a BCS game. If this happens than as expected there will not be a Big Ten bowl eligible team to fill the LCPB slot. There is a provision that a Sun Belt team will fill this slot but that is only if that team has a record of 7-5. That is not going to happen. Now the bowl is open to look at any FBS teams. They must take any team with 7 or more wins before a team with 6 wins. Ofcourse they will take a BCS team over a non BCS team. So here is the order of teams that I expect the LCPB to be looking at for the remaining bowl eligible non MAC teams.
North Carolina (should end up 7-5) This would be a good game for NIU but I don't see a 7-5 BCS team accepting this bid.
The below teams can be selected with a 6-6 record only after 7+ win Toledo and Miami (OH) teams get bowl bids.
Louisville - The Cardinals still need one more win to become eligible at 6-6. This game is close enough for them to accept.
Tennessee - This could only happen if Georgia becomes bowl eligible, Auburn loses to Alabama then defeats uSC and does not end the season being ranked in the top 2. This should leave LSU out of the BCS bumping everyone in the SEC down one bowl leaving Tennessee without a conference tie in game. Not to much further than Louisville this is close enough that both parties would be interested if there were no other options. Still a long shot though.
Army - Would be an interesting pick since NIU and Army are scheduled to open the 2011 season at Huskie Stadium. Army could end up 7-5 but doesn't play Navy until after the final bowl invitations go out on Dec 5th. If this is their only invite then they would accept.
Louisiana Monroe - If some how all the 7-5 & 6-6 BCS teams are selected that could leave Louisiana Monroe as the only remaining team that can be selected. This pickup would be taking one for the team.