Any OPML url will work in Jetstream, and it can be dynamically updated.
 Any new feeds that appear in the OPML will get added to the index.  I
eventually plan on adding an admin interface to make it easy to
add/remove feeds (or additional opml files) ad hoc.

My plan is to eventually open-source the software, since I'd like to
"give back" to the net community.  (And I'm using some GNU-licensed
libraries anyway.)    I would also like to make it a WordPress plugin,
but I think based on my current time restraints that I'll have to rely
on the O-S community to pitch in.

Until then, if somebody wants a customized version, I'd give them the
software but need to charge for my time to set it up (and support it if
needed.)

I'm trying to make it easy to put on a low-end box inside a corporate
firewall.   System requirements:  Webserver with PHP 4.3, MySQL 4.1,
and admin priv's to do cron jobs on the server.   I'm also using
server-side caching to lower the workload on the database.