When they fell off the other guy was clearly headed toward landing on Glenn. That's actually what I thought was going on with Glenn about to use him as a shield. In watching (and re-watching) that scene, it certainly implies Glenn is being eaten, but it's not a completely clear shot. The camera angle is low, not a clear top-down view until the end where it's a far away shot that does't show much and you don't see the other guy at all. Not sure how I'd feel about Glenn NOT being dead, but between the camera angles, other guy looking like he was going to land on him, and being at the base of a dumpster he could crawl under it's possible Glenn isn't dead.
If he still is alive, it's probably going to be at least a couple episodes before we see him again. Probably just Morgan back-story for the next show, then perhaps the group moving on or otherwise busy dealing with the W guys while believing he is dead. Maybe he'll show up (unless he's really dead) for the mid-season finale?