Right, so where's the video? Well, there's three. And all three of them have Lex Luthor, Superman, Neo, and Agent Smith in them...
Superman Unplugged 1 (http://www.youtube.com/watch?v=mwrb0gr8zjE&mode=related&search=)
Superman Unplugged 2 (http://www.youtube.com/watch?v=rAYpWiEpdqM&mode=related&search=)
Superman Unplugged 3 (http://www.youtube.com/watch?v=P5s8DP48dgo&mode=related&search=)
I think the actor doing Agent Smith is the closest to the mark.
Gah! ends just when it was heating up, you got to keep an eye on this one!!!
Great find!