Well, one of the achievements is to kill 10 enemies with one Mind Controlled Enemy. I've honestly never seen this function work too well in any existing games such as Bioshock. But if any game can do it right, Rage will be it. But what are your opinions on this ability?

WEll mind control in this is pretty simplistic...control and enemy and blow him up...it like ur own walking bomb.

Ahh. I was expecting more like make him start shooting his teammates. Is there a video of this?

I can't remember which video it is, but one of the videos on the RAGE website where he's going through like a basemant or tunnel area shows him switching to mind control bullets or something similar. It looked to be done pretty well. I'm looking forward to playing with all of the neat ammo types and stuff, and this just makes me more excited.

Try the E3 2011 Authority Video. They show the player shooting the Authority with this weapon and blowing him and a buddy up.

It happens at 5:18 in this video.
http://www.youtube.com/watch?v=8ui6j35YDbU