Ever since Eric Wood finished the 2010 season in the pivot - filling in for an injured Hangartner - we've debated here whether the college center entering his third season would supplant Hangartner at center. Over the long haul, I don't think there's any question that will happen; Wood is probably the best blocker on the team, and his best position is center. He'll be in there permanently at some point.
The Bills, along with the rest of the NFL, could very well be forced into a situation in which their pre-season preparations are accelerated - particularly if the lockout remains in effect over the next couple of weeks. Should that situation manifest itself, Chan Gailey and Joe D'Alessandris will likely aim for as much continuity as possible - and Wood has lined up next to Hangartner at right guard 20 times over the past two seasons.
It's probably not the ideal long-term solution, but in the short term, aided by the lockout, it makes more sense for the Bills to maintain the status quo on their interior offensive line.