http://packages.debian.org/experimental/amd64/jackd/download
will lead you to at least amd64 package of jack2 v1.9.4+svn3842. i386
packages should also be available soon.
-edrz
Thanks, all. Debian Sid (Experimental) has it very nicely. My install
is Debian Testing with Experimental repo enabled; I found that when I
did a Package/Force Version I got it with Synaptic. It pulls in a small
but interesting collection of packages, including a new dbus package.
J.E.B.