A lot of people have suggested that McCain ought to nominate a woman or a minority or a minority woman as Vice President to counter the excitement of having Obama on the Democratic ticket. My response has been that this is too cute by half; it is too much like picking Alan Keyes to move to Illinois and run for Senate against Obama. Also, while Governors Palin and Jindal might well end up being good Republican presidential/vice presidential nominees in the future, they're too young and inexperienced for this cycle. John McCain's most pressing need in a running mate is someone who can obviously move right into the Oval Office -- Dick Cheney, circa 2000, would be the perfect McCain VP.
I now suspect that McCain would love to put a woman on the ticket, as part of his wooing of Hillary supporters. And I'm starting to think that the right minority man would be ok, too. Colin Powell, for example, remains popular with the nation as a whole, and wouldn't be the turn-off for the Republican base that, for example, Joe Lieberman or even Rudy would be. (I know about all the inside-baseball Plame and went soft on Iraq baggage he carries, but no one cares about that stuff but us wonks.) Iraq works well for Powell because he can say going in was the right thing to do, W screwed up the execution, then W took McCain's advice and it worked.
In any event, I'm not actually suggesting Powell (I don't think Powell would do it, for various reasons). I'm simply saying that a woman or minority VP with gravitas and a reputation for competence could work well for McCain.