More likely than that, DC's replacement would not be regarded as a leading contender for the 2008 R nomination. If my highest priority were to secure the top '08 R slot, I would do everything in my power to dissasociate myself from W's failures. Being W's Veep would be the worst possible move for an R with future political ambitions.
I know you might find this hard to believe but most of us on the right totally support Cheney. He is a model of what a Veep should be. We also support Bush on 90% of his agenda. If someone with a similar voice as DC has is named he would be very highly regarded in '08.
What are the horrible failures you mention? (This should be fun.)