What I'd like is closer to, say, what Google Groups does, see e.g.: this article within the thread it's part of. But of course much more simple, and without the navigating frame and all those confusing "bells and whistles" -- I preferred the old UI btw, as you may guess.
Ive wanted a thread-view nodelet for sometime. Perhaps it will eventually be implemented by someone. Most of the infrastructure is there to do it already, its mostly a question of whether such a nodelet would add too much load (IMO it wouldnt) and finding some spare tuits to actually put it together.