He has an answer to 'Why hasn't Mann been fired?',

and he's fairly brutal about it.  Rightly so.  And anyone who says "But he's not a real scientist!" didn't bother to look at his background, or is an idiot.
His letter is long, and damning for today's scientific establishment.  And he specifically discusses Dr. Mann, and why Penn State did not (and will not) take any action against him:

Some have held that the physicists of today are not as smart as they used to be, but I don’t think that is an issue. I think it is the money, exactly what Eisenhower warned about a half-century ago. There are indeed trillions of dollars involved, to say nothing of the fame and glory (and frequent trips to exotic islands) that go with being a member of the club. Your own Physics Department (of which you are chairman) would lose millions a year if the global warming bubble burst. When Penn State absolved Mike Mann of wrongdoing, and the University of East Anglia did the same for Phil Jones, they cannot have been unaware of the financial penalty for doing otherwise.

Borepatch has a lot more in the post.