He has a few good songs, nothing on the level/staying power of a michael jackson/elvis, etc.
Tonight on Sat night live, he was doing the vocals to aerosmith, katy perry, louis armstrong, and a few michael jackson. He sang them better than the originals, I thought. No video available yet, I'll try to post it.
I'm trying to think of a better pure vocalist in the last 5 or 10 years... I can't think of one.