I'm a bit late to the table with this, although this morning's news release with Nike dropping their sponsorship commitment and him stepping down from LiveSTRONG's chairman position makes it a bit more timely...
This is the tale of human nature, the tale of somebody who valued winning above all else, but also the tale of somebody so profoundly impacted by his brush with death that he created a foundation for it.
I don't think Lance Armstrong is the devil if, in fact, the USADA case against him is true. It sounds like the conspiracy to dope ran through the entirety of cycling: from teams, to team leaders, to the riders, to the organization that sanctioned the professional tour. It's sickening. And it is through that lens of "doing whatever it took to win" that he valued winning over clean sport, when it sounded like there was no such thing as clean sport during that time.
That doesn't make what he did any better, though. It's cheating. It flies in the face of why I compete; to see how I stack up against my fellows, and to give every ounce of my being to it. Someone else values winning more than that, and they'll do whatever it takes to get there. That can lead to some pretty dark places, and it appears it took Lance there, too. Makes sense, if you think about it: incredibly competitive person wants to do whatever it takes to win.
But I also think that his doping history also does not disqualify him from the good that he does with LiveSTRONG, either. I'm not going to fight a LiveSTRONG argument; that organization did a lot for my family and I when we lost my father-in-law, and I'll happily continue to wear a LiveSTRONG band so long as I have one.
It goes to show that professional athletes are indeed human, and can be doomed to the pitfalls of our nature as well. But that means you be both things: Lance the doper, Lance the charitable.
I don't think it makes much sense to separate the two; nor do I think one disqualifies the other. I think he's human.