it would be very useful for intranet web applications to have a Kerberos Authentication module like the one for apache httpd (http://modauthkerb.sourceforge.net/) and the lighttpd one (http://redmine.lighttpd.net/issues/1899).
Already underway - I've got a guy at RentACoder working on it, and I'll be trying to get it to a point when we can release it and let other people fix it up, test it, etc.