Some folks think
Cheney is moving inexorably toward resignation. And there are certainly no shortages of arguments as to why this may be occurring (see Libby trial).
I just don't see it happening.
Beyond the pure power-madness of Cheney, stupid-stubborn loyalty of Bush, and oppositional nature of Bush, there's another reason Cheney won't be thrown under the bus.
Cheney is one of the greatest protections against Bush being impeached. Remember, a newly appointed Vice-President would have to meet the approval of Congress. That means that the V.P appointment would have to be decent, given the Democratic majority in Congress. If Bush puts up a nutbar, Congress can simply sit on it's hands and allow the space to remain vacant which would mean that Pelosi would be next in line.
No one wants to see Cheney as President, so he's Bush's best bulwark against the whole impeachment thing.