Armstrong’s collar bone was broken into several pieces (as opposed to more common partial fracture or single break) and is now liberally screwed and plated together. Impressive bravery to take part nonetheless.
His stated aim is to ride for Leibheimer, which he is doing. I’ll be very impressed if he completes the distance, and doubly impressed if he completes TdF. Winning is out of the question, I think. Even a stage win is extremely unlikely, because of his age and lay-off, not because of his collar bone (although that is not exactly a help).
I have to take my hat off to him, coming back is a very brave move. But I can’t see him winning.