Don,
Like you, I called Helm. They had no idea when it would be available, and gave me Hummer's phone number to call. I called Hummer, they put me on hold, called the dealer, then transferred me to the dealer after they had talked them.
The dealer says he has ordered the CDs, but they have not yet come in. I'll post an update when they come in.
On my own, I discovered that folks are selling the si-2000 CDs on Ebay. They have, as you say, all the GM service info. I bought a set on Ebay for $35, and it does have Hummer info. Unfortunately, the CDs appear to be issued every 2 weeks, and GM's web site has an update patch that comes out between CD updates. The patch will only work on the latest CD release, so without getting the latest CDs, the info will get old. BTW, the GM site is
http://service.gm.com/
Klaus