I think this could be a fun matchup to watch. It would be entertaining on the feet or if it goes to the ground. Sonnet would call it a loser leaves UFC matchup. 
Edit* Sonnen
Leben wont be fighting anybody for a year 
That would be a fun fight to watch!
I would love to see it.
In a year.
I'm not an '11 TUF noob. I know Leben is suspended.
This would be a fun fight to watch, in a year.
OaktownWhiteBoy -axxesmerdas - Leben by brutal ko. Big power difference.
Feather fisted Mayhem couldn't break a grape!!!
LMAO
Say what u want about mayhems power, but the Guy has never been koed and normally has decent defense. Dunno what happen the other night but I don't think leben ko's him easily
See: Leben vs. Rosholt
Mayhem vs Cung Le
or
Mayhem vs Wandy
I RARELY pick Chris Leben to win, but I think he'd be the first to really hurt Mayhem with punches. Mayhem's too wild to want to go punch for punch with Leben. And Leben has a wrestling base, so I don't expect consistant takedowns for Miller to work a sub.
Mayhem vs Stann, Mayhem vs Okami. Cung Le is a lose/lose situation for Mayhem, if he wins, he just beat another over the hill fighter like he did with Sakuraba, and Cung Le is a stylistic nightmare for him. If he can't hang with the big dogs in the UFC, he shouldn't be there, he was brought in as a contender (and paid like one I am guessing).
thing is, SF is staying. Miller is exactly the type of guy who should be in SF. He can't compete with the best, but has name value, and can put on exciting fights.