There is a mailing list for Jambi that appears to still be active. You can view some recent posts about this topic in the archives. There is one response that appears to be from a trolltech employee about the future of Jambi but It doesn't really seem to say much more than their press release does.
Tue Mar 10 14:37:29 CET 2009:
We are hoping that a community of contributors will develop for the
coming year, and will try to help make that happen. After that year has
gone by, neither of us will be able to spend time on this project at
work. But if there is a thriving community at that point, I wouldn't
expect either of us to disappear completely either :-)
We have spent some time on this
project, and we definitely wish to see
it succeed out in the wild. But, as
you say, we cannot commit to anything
beyond what we have spare time for.
A year is a long time in terms of
spare time, so right now I'll only say
that I hope there's still interest in
a year, and I hope I get the chance
to help out. :-)
-- Eskil
There is another post where they mention that they are still expecting a release soon. The latest code can be found here.