Thanks for getting back to me! I can't believe I didn't think about that..
With the release of Xen 5 from Citrix (for free!), I changed my direction for this customer.
Funny, though. Your article made me get totally immersed in the drbd stuff. I had always wanted to get more into the cluster stuff, but just never jumped in and started reading. Now, the drbd stuff (with Heartbeat) just looks like it could do SO much.
Again, thanks for your post!
..and if you haven't seen the new free stuff from Xen, you should check it out. It does the VMotion stuff.. (which is what I was really interested in for this customer).