My impression is that Frank could probably move on despite The Incident, but I don't think he really wants to. When I talk with him I really get the impression that he has immensely enjoyed building the program to where it is today and that he'll be happy retiring here when he either gets tired of coaching or feels he's losing his touch. I hope that's a long time from now!
I don't think the incident would have much impact on anyone looking to hire him as a coach. It would come up, of course, but not prevent the hire since it was a single incident, and now years back into his history. The real factor that makes it unlikely that he moves is probably his age. Building a program takes a lot of energy and commitment, and a lot of years. Think about Ohio. There was no magic wand waved in 2005, though the Pitt game was a magical moment. Even 2006 was not magic, it was merely a huge effort and hard work by an over-achieving bunch of players that really wanted it. Instead what you've seen is a few high points (like the 2006 season) and a few lows (like the 2008 season) superimposed on a generally rising trend. Now, seven years later, Ohio has a solid and respected program, and lows will be higher lows, and highs will be higher highs (and I still think 2011 will be one of those higher highs).
If some other AD came in and hired Solich, would Solich want to put in another seven years at this point, building something else from scratch? I'm guessing here, but I have to think Solich would be proud of what he has accomplished at Ohio, and would be content to someday retire, leaving his accomplishments at Ohio as what he is known for.