Colin Powell on Team Obama?

What a crazy road it's been with these VP picks. It was only two months ago that Colin Powell was being floated as a potential VP candidate.
Now a scant two months later, the rumor mill suggests that Colin Powell is ready to endorse Barack Steve Obama. He's got a big day tomorrow on Meet The Press, possibly capturing at least two or three news cycles.
I can't help but think that this is would really be a huge pull for independent voters. Personally, I think that if Colin Powell wasn't too smart to be President, he could give Obama a run for his money in a race. How would the McCain camp downplay the endorsement of a loved (centrist Republican) figure?