Please, people, there is absolutely no evidence that the VP's health is getting worse, and plenty of reason to think otherwise. He has made it clear he's staying for the duration. What else is necessary? He is not going to want his legacy to be that he did not serve out his full-term for political reasons. Furthermore, Dick Cheney is a valuable asset to the President on Capitol Hill and in the Oval Office as a trusted advisor, probably his most trusted advisor.
If Condi were appointed to the VP position and went on to run for President, she would be forevermore depicted by the Dems as being handed her position and her political career as a gift from the President, rather than earning it. It would not be a good thing for her or for the Republicans.
Wow! That would be a lot worse than the things they say about her now.