Yesterday I added a new mutt version to the tree (1.5.11, ~arch). Except from a bug regarding SASL that I fixed a couple of hours after adding it; should work fine.
I also added maildrop-2.0.0 to the tree AND package.mask. This version comes with nice features such as fam integration and uses libpcre for pattern matching. Please test it and send bugs if you find any. I’m using it without problems so it shouldn’t break too badly 🙂
# echo '>=mail-filter/maildrop-2.0.0' >> /etc/portage/package.unmask
# emerge -va maildrop
should do it.