I'm quite worried if Hillary wins the primary. It'd be tough "mixing it up" because most men would be very uncomfortable voting for a woman in the first slot. If Rice has first slot, we'll be battling low turnout for 2 reasons: (1) prolife vote unless Rice makes very strong pro-life changes in policy, (2) men won't be enthusiastic about choosing between 2 female presidents. But if Rice is in the 2nd slot, that'd scream "token black female" to many people. It'll be very, very tough selecting the right candidate if Hillary looks like she's a shoo-in to win the nomination...
If Hillary doesn't look like she's winning, we'll have a much wider field to pick out from like you note.
2008 is a long time away though. If you asked FR if John Kerry could win the nomination, you'd get a lot of laughs.
"I'm quite worried if Hillary wins the primary."
I wouldn't be concerned at all if we nominate the right candidate. A "red state", socially conservative leader with very strong personal morals and conservative principles. And then paint Hillary as the New York liberal, radical feminist, unprincipled carpetbagger that she is. And, if you had somebody with true conservative principles, you could make fun of her changing views on immigration and her other "sharp rightward turns." And then go out there, and clean up with every socially conservative voter, blue collar men, and the anti-Beltway crowd.
But, running Giuliani or McCain, it looks like she a clear shot. I don't understand how Giuliani, for example, would differentiate himself from her. He has bad morals too. His positions are very similar, and she will be to his right on several issues (immigration, etc) by 2008.