This is somewhat odd, as you have Mike, Kevin Murphy (the Tom Servo we all know and love), and Bill Corbett (Crow in the SciFi years) have been doing their own thing for awhile now (Rifftrax, The Film Crew, etc) I always found Mike much funnier than anyone else - from listening to his post MST3K riffing stuff, it's pretty clear that he was the main guy, even when Joel was on camera.
Still, this should be interesting. I'm a huge fan (I literally own every episode on DVD), so I'll be sure to check it out.