Some of the choices he has made and policies he has pursued could be chalked up to pragmatism, I suppose (continuing the wars, budgetary choices, etc.). I don't agree with a lot of it, but maybe in some cases the choice was unavoidable. The one I can't stomach is the FOIA thing. That is a conscious choice when a huge part of his campaign was based upon restoring transparency to government. On this, he has been disgraceful. Romney, if his tax returns and his record as governor are any indication, will be equally bad. I never thought it could be worse than Bush/Cheney.
My biggest disappointment is his failure to renounce torture and assassination by the state. The USA has conceded the moral high ground on these issues, and it's a damn disgrace.