I could see Webb joining Obama. I think McCain would win if he could align with Huckabee.
I second the Obama/Webb ticket. I was shocked to see the new GI Bill he drew up (in a good, kind of speechless way) and generally like his no BS attitude. However, I disagree with the McCain/Huckabee ticket being a winner. McCain is only doing as well as he is (which state by state shows not very well) because of independent voters somewhat split between McCain and Obama. You throw Huckabee in there and it will motivate the base a little more, but drive away those independents who are tired of the religious right. The base really hates McCain, which is a huge problem for him since he's going to need to be able to find a way to pick someone who'll motivate them without driving away his independent voters. I don't know if such a balancing act can be accomplished.
The base is no fan of Huckabee either. He is pro-life/anti gay marriage, but on any issue that he actually has the potential to influence he is no conservative. He has a long record of tax increases, he feels that it is a "biblical obligation" to fight global warming, and he called people who backed a bill requiring proof of citizenship to register to vote and receive certain social services "un-Christian and un-American."