Cheney's medical status is in the news from time to time--announcements that he's fine, but of course reminding us that he's got a troubled ticker.
I still think (I predicted this before Bush's re-election, but was wrong) that he'll develop a weakness before the end of Bush's tenure and will be replaced with someone that Rove would hope to install as Bush's successor nominee of the Republican Party.
Am I crazy? No. I know Rove has thought about it, don't you?