Hardball arguably offers the most intense political analysis, and they are sizing up the VP competition as following:
McCain's top 3 in what Harball says is the increasing order of likelihood of winning:
3. Former Rep. Bob Portman
2. Governor of Minnesota Tim Pawlenty
1. Mitt Romney, Former Governor of Massachusetts.
Although Romney is a good pick for McCain, I think they missed the boat here. Another smart choice is Kay Baily Hutchinson to peel away the Hillary Supporters still reeling from the Obama defeat. As a woman she'd pull more total votes than other VPs, though I'm not clear if that support would come from the necessary states. Still, enough states will be close that the best VP strategy is a powerful *national* support getter.
For Barack Obama:
3. Senator Evan Bayh
2. Tim Kane, VA Governor
1. Joe Biden, Senator from Delaware
I think two senators are weak on a ticket, so it'll be Tim Kane in this group but I think more likely is Wesley Clark, a smart and sharp campaigner who could put to rest any military challenges to the ticket.