That was sweet! I saw some other vid one time with RDJ singing, but this was even better.
What's interesting (to me anyway) is that he obviously has a good voice, but singing isn't just about the quality of your voice; it's what you do with it. And as an actor, you can see him "acting like a singer" in that performance. He puts on a persona of a singer, based on Sting as far as I can tell, and it comes out great.