I'm with Truth and 3lions here. Having Flair win one more time to honor his dedication to the business and to give the fans an emotional moment just isn't smart for the business. (It certainly isn't the same as giving 'Taker one more reign at WM this past April.) He's been "down" for so long, to give him any credibility for a title win, I'm not sure there's enough time to give him the proper buildup for a title win to be anything close to credible. (It would have to revolve around the "Dirtiest Player In the Game" and even then, it'd be a stretch.)
I think Flair wouldn't necessarily be TOO opposed to one more reign, but I also think he's one of the few guys who worries about putting over guys for the future of the business. (Even more so than say Mick Foley or Chris Benoit or Shawn Michaels.... and the last two really haven't started/needed to start doing that till late.) He's more worried about that and leaving the business in good shape for the long haul than anything else.
I just don't see one more run for him, nice as the moment would be.