Actually, I can think of a few, but the point is that Jeb Bush would have a better chance of beating Hillary Clinton than Condoleezza Rice. As a matter of fact, the only way Bush could possibly run and win in 2008 be if Clinton was his challenger, in which case all nepotisism charges would be moot.
My personal candidate for 2008 right now is Newt Gingrich (should he run), but keep in mind that Governor Bush of Texas did not become the frontrunner in 2000 until after the South Carolina primary. The fact that no name jumps out at you right now doesn't necessarily mean anything more than that several perspective candidates have thus far avoided putting their names in play.
This much I can promise you: Condoleezza Rice will never be President of The United States, so get that idea out of your head.
I love Mr. Newt and would vote for him in a heartbeat (he has even come out on Rush against illegal immigration, unlike the current administration.)
BUT, don't you think his reputation in the MSM from a few years ago would be hard to overcome? Most people, sad to say, don't really think for themselves. This excludes Freepers, of course.