Oh I don't even KNOW anymore. He seems to have either sold out, or maybe he feigned "edginess" back in his early days. It does seem, in hindsight, like much of his appeal from a few years ago was no more than a gimmick.
But doesn't the transition to mainstream happen with just about every 'edgy' comedian? It takes a rare person not to sell out and still be able to remain successful, either in performing or being able to make a living.
Digressing further, I think that's the appeal of Stephen Fry. He has been able to enter the mainstream whilst remaining as delightfully witty as always. The man has charm in bucketloads.
I think the problem with Izzard is that he was so adamant that he wouldn't go mainstream because it wasn't what he was about. He harped on about it in many shows and interviews.
I guess we can all be wrong about our motivations and beliefs, and everyone has the right to shift their philosophical outlook on life, but when you state that you have a certain outlook so vehemently and then u-turn on that completely, you have to lose some credibility in the eyes of those people who believed in you originally.