My family/friends guild is already level 3. I've leveled my 5-pally team through Vash'jir, Deepholm and Uldum (just started Twilight Highlands last night). A friend who single-boxes is just out of Vash'jir and only 82, and my mother has been dual-boxing her two hunters from 76-79 since the expansion went live. So we've not exactly been doing all that much. I suspect it'll slow down some once we're done leveling and focusing on things like tradeskills and dungeons/reps. We'll see.