sings: "Ch-ch-ch-changes!"
Sorry. David Bowie read the thread title and was dying to come out. Anywho, I would use the sort function to do a few different things:
1.) I'd sort by replies. Sometimes, I wanna hop in for a ten minute break in my day or something, in which case I'd like to be able to see which threads are the hottest, most happening threads and focus my attention there.
2.) I'd sort by forum, although I admit this would mostly be to relegate all of those Slaying Practice posts to the far away land of the "S"es. I guess it would be even better if I could selectively enable and disable some forums, but sortability would probably be easier to incorporate.
3.) I'd sort by last post (by member name, not by date and time). I'll be honest, here: some folks' opinions interest me more than others' interest me. If I see a thread with, say, PVsBestestBuddy09 listed as the last poster rather than, say, JoinedAYearAgoAndOnlyPostedTwice, I'm more likely to pop into the Buddy thread than the slack-off poster thread.
I tend to use the New Post list as a quick introduction to what I missed between logons -- especially if I'm low on time. For me, then, having the ability to quickly sort that list in order to highlight things that most interest me would greatly enhance this functionality.