Franchise him and then if we are fortunate to draft Dan Williams, maybe we can look at offers to trade him? This is similar to what Pats did with Cassel last year.
Have very little to lose IMO, except making Snack a little angry. If we can't get Dan Williams or another replacement candidate NT in the draft, then we can look at working out a 3 or 4 year deal with Big Snack, and try to backload it (similar to Farrior's deal).
If we do get Dan Williams, then maybe we can trade Snack for a 2011 3rd rounder.