Good news... jack-audio-connection-kit is in extras-development.
Also, about 6 months too late, I watched some of the videos from the
Boston FUDCon a few months ago...
The videos include a talk about sound on Linux, and it touches on jack,
LADSPA, etc. The presenter, Chris Montgomery, talks about a plan to
write a new sound server for Fedora that will satisfy both real- and
non-real-time audio applications. I don't know if anything has come of
that yet, but it would be interesting to hear an update if anybody here