I have yet to miss a stage (rather, the last half of a stage, since that's whenI get up). Lance will have a VERY hard time winning this year. I think beloki, hamilton, and ulrich will give him a real run for his money (although ulrich raced horribly today). Everyone who's ever won 5 tours has said the 5th was by far the hardest.
My prediction is lance wins, but not by much, and I think it will be a back and forth battle between him and some of the other great riders (ulrich, beloki, hamilton, mayo?).