Ok, Ok, just hear me out on this one because it kind of makes sense. My hypothesis is that Armstrong isn't going to just pack it in on his last ever tour. I think he's actually pretty fit, and he only got himself 13 minutes behind because of a couple bad crashes that left him banged up and dispirited (a la Jan Ulrich and his 1998 loss to Marco Pantani). Honestly, it's the easiest thing in the world to lose an eternity in the Tour de France...those guys are FAAAST!
Armstrong is pretty much out of the running (unless he has a big Testosterone party like Floyd...which I seriously doubt he's going to do). However, in a weird way, that makes him sort of dangerous. He's not a threat anymore, so it's likely that he could do some kind of random, reckless, Thierry Marie style break away at the beginning of some major mountain stage.
Are you thinking that Armstrong isn't a good enough climber anymore to win the Polka-dot jersey?
Well...let me just draw your attention to Laurent Jalabert who won the king of the mountains in 2001 and 2002 (he's one of the few riders who has won both the sprint jersey [1992, 1995] and the mountains...pretty bad ass really). Honestly, they used to say Jalabert was a great "day" rider (sound familiar Lance) and when he lost the fast twitch of a sprinter, he just came up with a Polka-dot strategy.
What was the strategy?
Be a great "day" rider on a couple big mountain stages after you've given up about 13 minutes and win all the climbs without really having to contest them like you would in a traditional mountain sprint. Then, just do your best to be in the mix in the "sprint" climbs (if Jalabert was within spitting distance of his competitors at the line, he was going to take that sprint).
Meanwhile Levi can putter way to his typical 4th place (seriously...does anyone think he'll do better than that?).
I think the Polka-Dot Jersey would be the perfect coda to Lance's career, and he wouldn't be the first former champion to bow out that way. Remember old Bernard Hinault in 1986...yup, he was splattered with Polka Dots. And remember that grabbing that Polka dot jersey gets you on the podium for a "jerseys" commemorative shot. It'd be nice to see Lance there.