I hold my nose at the possibility of it being Colin Powell if Obama wins the democratic ticket and it seems that McCain is an underdog because of the African American thingy...
I do hope it is Romney or some other half way decent republican.
Just putting a Black person on the ticket wouldn't do much to get votes from Blacks. Many Blacks aren't fans of Condi Rice.
And I doubt Powell would accept the VP nomination. When he was Secretary of State, I think he supported the idea of sending Paul Bremer to Iraq to replace a general, Jay Garner. Based on Powell's military background, that made no sense. And he would need to defend why he didn't argue against the "Rumsfeld strategy." And then there's the speech he gave at the UN. So it gives him less credibility.