Hi Antony,
It's a shame this hasn't been looked at yet. I hope ardour makes it into Lenny.
Various people are working on this - the latest plan is to get a new release of libsndfile upstream, so that Ardour doesn't need to embed a copy.
I have been doing a little research into this, and according to
http://ardour.org/building, there is:
SYSLIBS
USE AT YOUR OWN RISK: CANCELS ALL SUPPORT FROM ARDOUR AUTHORS. Use
existing system versions of various libraries instead of internal ones
(yes|no)
It's really not a good idea, because the system libraries don't yet have the patches that Ardour needs. That's why the upstream authors can't support a syslibs version.
is it more important to have upstream support or Debian security support?
We're aiming for both :-) Cheers! Daniel