I had lunch with a bunch of GM Truck engineers this week, all former co-workers, and mentioned this to them. The concensus was that the Astro had pehaps one more year to run, as the Baltimore plant where it is made has no product assigned to it past 2005.
When I was with GM Truck, there was a brief program for the Astro/Safari replacement, (GMT 710) but it was cancelled early in the development stages, in '98 or '99, if my memory is intact. I know we spent nearly a year hand building the new body, only to see it moved outside to rust away!
Since I had the information, I thought I would pass it on.
Jeff