I've been hoping for the folder tracks, similar to those in ACID, for a the last one or two versions of Vegas now. It seems like a pretty popular request. I'd like to see it soon too.
I see the folder tracks just as valid (if not moreso) as in Acid. Specfiically with the Video emphasis - separatae dialogue, backing music, and SFX sections, easily hideable so as to not clutter the timeline.
Could still be folders, one folder per buss.
Have icon in buss fader panel to expand / collapse.
Just seems logical to me. Send all the drum tracks to one buss, not interested in the drum mix, collapse all the drum tracks. Want to mess with the drum mix, expand etc.