I saw a review for the new Doom game, and it had something that might be pretty cool in Guns. The hill moved, but not instantly to a new place. Rather, the hill wandered on a set path (at least I think it was set).
So, the setup is this: Grab an escape balloon from Alliance, and set it on a path on whatever maps. Give it a 'capture' radius like the current point balloons. Let it go. It would then follow the path with players having to stick with it to capture/keep the enemy from capturing. Like the current KotH, you would have to remove collision on the balloon or give it a zillion weight so it could not be knocked off course.
This would add the interesting aspect of constantly having to reposition while tracking the blimp, or setting up ambushes and letting the enemy come to you.