As Steve McIntyre regularly reminds us, it is unlikely that any of the famous climate scientists will be proven to have committed outright fraud: making deliberately false statements in order to acquire a benefit such as a grant; saying one state of affairs is true--regarding temperature or whatever--while knowing that a different, equally specific state of affairs is actually true. It is unlikely that they have published things they know to be false, while suppressing things they know to be contradictory and true. They are not hiding proof of global cooling, or even of a global steady state in regard to climate--there has probably never been such a thing.
What they have certainly done is give a misleading impression as to how much certainty is possible in their young science. Their very precise numbers and graphs are misleading, not primarily in comparison to a better set of numbers (although in some cases there probably are some), but in comparison to the genuine uncertainty that remains necessary in any statement of findings.
I keep going back to the e-mails in which leading climate scientists, in communications that they believed would never be public, admit this to each other. See here and here. It has been said on good authority that during the Oxburgh inquiry, Phil Jones said that it was probably impossible to do the 1000-year temperature reconstructions with any accuracy. See the Phil Jones interview in February.
UPDATE: See also John Christy.