Vice-President Cheney is, let's be honest, an embarassment to Bush, if not a total liability. He has made spurious claims of
Iraqi links to al-Qaeda, made ridiculous claims
that the Dems could have made the economy worse and there are his links to Halliburton which draws scandal in like fly-paper.
Republicans, contrary to popular belief, aren't all stupid and a lot of them are turning on Bush thanks in large part to his bloated corporate welfare bills, mishandling of the economy, culture war politics and plans to give undocumented Mexican workers legitimate status.
Could the "rumours" of Cheney about to be dropped from the ticket be a calculated move on the part of the White House to entice disillusioned Republican voters back to Bush? Is it possible that the noises about Cheney are a concession, to show Bush isn't completely irresponsible?
To answer the first question: probably not - but would you put it past them if it was? To answer the second: yeah, like that will ever happen.