Before getting a real kit, I would like to test it first. But so far I have not been able to find it for download anywhere. The officiel free trial page only allows you to order the kit on a DVD - not download.
Today, I found the evaluation download on connect and even better an evaluation version of Windows Home Server Power Pack 1. Power Pack seems to be Home Server'ish for Service Pack and some new features. You can get a prerelease version of the release notes from connect.
As soon as the download finishes, I will load it up in Hyper-V :)