Although we have not yet approved Vista SP1 for distribution via WSUS, I have worked with the beta and recently installed the release version via Windows Update. After the install, though, I was seeing errors when my system tried to renew its activations against our KMS.
When I ran
slmgr -dli, it reported that my version of Vista was Enterprise Edition but also Retail Channel. I posted a message on the MS Vista installation and Setup forum, and a helpful Mr. Gorter suggested I change the product key, as documented in the Volume Activation 2.0 Deployment Guide.
I updated the product key and successfully activated against the KMS. I will be keeping an eye out for the next opportunity to install SP1 to check the product key before and after install.