I think that's a bad idea. People like changing governments every decade or so. Condi MIGHT be able to pull the premise off, that she is not a continuation of this administration, if she is only a cabinet official. As a Veep, it would be impossible.
Condi for president has a huge boat anchor to lug around. George Bush. I don't even know if she'd carry a majority black vote. People will see her as Black W out to steal yet another election. Not that many of the lunatic left would switch over, but I believe many right in the center wouldn't vote for her, just for the reasons you stated.
Those same people that held their nose and voted Bush because Kerry was such a putz would hold their nose and vote Hillary JUST for the Change. I would vote for Condi but I don't think she'd win for all the reasons listed in this thread. Hillary becoming president is truly frightening though. The incredible transformation from a raving leftist to a conservative Christian is taking place now. I hope no one falls for it.