For a number of months, there is now a forked version of mutt called mutt-ng. I just tried it today the first time, and I really like it. It's good to see mutt development is moving again.
I'm not even sure how much time mutt-ng will save me through it's maildir header caching. That saves the ridiculous delays when navigating through my 130+ folders 4GB maildir spool :)
Next item on my personal wish-list would be threading across multiple folders. I'm missing that feature ever since I stopped using CrossPoint (DOS-based mail-reader software for FIDO,Z-Netz,MAUS and UseNet) in 1994.