Phillip - you bring up some good points, but if you see Kerry rising in the polls even a little bit - to the point where he may win on a fluke, you will see Hillary get the VP nod. She can't slip into obscurity and risk waiting until 2012.
I think the whole idea of Hillary Clinton running for president, whether in 2008 or 2012, is fun speculation but it won't happen. She's a lot like Newt Gingrich, in that she brings a lot to the party in terms of raising money and energizing the base. But like Gingrich, making her the official head of the party would be an electoral disaster for the Democrats. The benefits simply don't outweigh the negatives.
I've always thought that the first female president will be a moderate, pro-life Republican. I don't think the country will stand for a female president who is a pro-choice, feminist, liberal Democrat. In a Presidential election, Hillary Clinton would win the northeast, maybe California....and that's it. She won't even be competitive in most of the traditional "battleground" states.
Along the same topic lines, there's also a question of who the Republicans will run in 2008. male private part Cheney is widely dismissed as a possibility. Condoleeza Rice gets my vote. Did you see her testimony before the 9/11 Commission? She's a strong, incredibly smart woman. A Rice vs. Clinton matchup probably won't happen, but it sure would be fun to watch.