Note that the most recent timeline at the time of writing is this:
http://lists.debian.org/debian-devel-an ... 00003.html
And the last release update (without timeline) is this:
http://lists.debian.org/debian-devel-an ... 00017.html
And that the timeline has slipped, release in september is unfortunately not going to happen. See
this page for a list of current blockers.
And no, it isn't yet known when the new Sarge will be released.
--Jeroen