My opinion is that Armstrong must have doped. It is impossible for him to have been that succesful in an era where all his competitors have since admitted they were doped up too.
I wouldn't judge Armstrong (the cyclist) too harshly. How on earth was he meant to compete clean? Everyone around him would have been pushing him towards it. Starting off with the odd injection to recover and before you know it he's on the EPO and blood transfusions. I'm pretty sure the UCI is implicated in his story too.
Then there is Armstrong (the cancer survivor) who gives hope to so many people when they are facing up against this terrible disease. OK the story changes a bit. Maybe not quite as spectacular as him doing it clean but again I don't see how this work has been cheapened as a result of him doping.
As for Armstrong (the brand) I think the c-bomb by Bradley Wiggins in the press conference the other day would be well used here. I just don't like him.
He's gone too far to back down. He's flung too much mud at others to then say he was at it too. He will never admit to doping which is a shame because he could do so much good for the cause.