I have wanted to install SL Client on my 2010 mini server since I got it back in early May, but never had any luck using a retail SL disc. I read various forums which suggested that you need a 2010 standard Mac Mini restore disc to best accomplish this. I got my hands on a restore disc for a Mac Mini client and using my usb superdrive, I was able to install it, apply all of the updates, and viola! I migrated my account and apps over from my time machine backup. Everything seems to be working fine! I also changed the dual drives to a raid 0 stripe set so that I would have a single big drive. Now when Lion comes out, I should be able to upgrade easily to the client version. Can't wait to try out Lion!