Those saying McKelvin played pretty well were watching a different game than I was. No one says that McKelvin can't run with the top WRs, and if that was all there was to it, he'd be a top corner. He's a great athlete. But he puts himself in bad position frequently, does not look back at the QB or the ball, and has poor ball instincts (4 INTs in 3+ years is piss-poor for a top-draft-pick CB). His awareness hasn't gotten better, and he doesn't look in command of the game at a time when he should be looking like a veteran defender. To boot, emulating his guru Dick Jauron, he thinks he played pretty well yesterday despite his failures.
No doubt Moore and Campbell played lights-out. But they also picked on McKelvin all day, which says something to me.