I've finally got it to work, kind of .. It should allow you to log in, but several settings don't work yet and there are probably many bugs. Anyway, I thought I'd show this already in case someone is interested of looking how it works :)
One thing I'm still wondering a bit is if I should show process names as:
32602 pts/19 S 0:00 dovecot/config 32603 pts/19 S 0:00 dovecot/log 32604 ? Ss 0:00 dovecot 32606 ? S 0:00 dovecot/imap-login 32607 ? S 0:00 dovecot/auth -s 3
Or if I should name the binaries all as dovecot-config, dovecot-log, etc. One nice thing with the above is that it also shows imap and imap-login processes while grepping for dovecot.
You can get the tarball from http://dovecot.org/tmp/dovecot-1.0-test67-mrewrite.tar.gz (it has all the test73 changes despite the name..)
Example configuration file (with bare minimals) is at http://dovecot.org/tmp/dovecot.conf
I think I'll create a separate dovecot-master.conf for those service-blocks in the above config file (after I add include-directive to config file parser code).
After the code is working better, I'll commit it to CVS and it'll be in future -test releases.