Not sure if this is of interest to everyone (anyone?) but it caught my
eye and might be worth paying attention to.  First message in thread
is:
    https://www.redhat.com/archives/fedora-devel-list/2007-July/msg01537.html
The "easily ported from rpm5.org" note is interesting.  Also many of
the feature requests seem already implemented (or started) in rpm5.org
codebase (soft deps, etc.).
Jason