I'm with those who've suggested the pole arm or staff-fighter that inflicts status effects on enemies - stuns, trips, dazes, immobilize, slow, etc... lots of burst 1 effects swinging the sticks or pole arms and zapping lots of enemies. Lots of shifty abilities could let him move around zapping other groups.
This type of character really belongs in the Asian-inspired book that has the Ki power source - and hopefully they put in all the martial weapons that will support it... sai, tonfa, jo sticks, bo sticks, etc. Will that be PHB3?
I agree it would have been cool if the monk was the martial controller, but we could still see it as a similar class.