I think the McCain campaign's "Celebrity" ad and the whole line about Barack Obama being too arrogant or something are pretty ridiculous, but it's a bit puzzling to me to see liberals expressing the view that these are some kind of crypto-racist lines of attack. Given that Obama's black, and America's history, I think it's always going to be possible to read some kind of racial subtext into attacks on him. But both of these are lines of argument you could easily imagine being deployed against a white candidate and, indeed, they're fundamentally similar to arguments Republicans regularly make against Democrats.
Beyond that, trying to sniff out racial subtexts in these kind of things strikes me as overwhelmingly likely to prove problematic. People really don't like to be called racists. Obama really has had a brief tenure on the national stage and most people really aren't especially familiar with his legislative record or his agenda. If people hear about Obama's record their doubts may be allayed. If they're told that their doubts are really just racism, they get defensive. Personally, I think Obama's record on getting police to videotape interrogations speaks extremely well of him. For one thing, he was right on the merits of the issue. But beyond that, this is the kind of thankless cause that politicians normally avoid. Even those who might be willing to back a measure of this sort are rarely going to decide that it's worth investing actual time and energy in it. And Obama showed great skill in, over time, growing his coalition and defusing the initial opposition of law enforcement groups -- getting them to see that at the end of the day serious law enforcement professionals have nothing to fear from high professional standards and meaningful efforts to see that justice is done. But how many people know about this stuff?