All of the patrolling can be done in Hammer with paths, although probably some AI behavior would have to be tweaked to mimic GEN64's. Regardless of how cool singleplayer would be, I think everybody's stance on it (including my own) is to get multiplayer as tip-top shape as possible. Singleplayer would be more of a side project after the multiplayer's very close to or at 100% completion, I reckon. I'm putting words in everybody's mouths here, though.