Steve didn't make any note of Leopard server in his Keynote, which is a little sad. I can imagine all the engineers who work on the server OS waiting, hoping that Steve would note all the cool new features. Sadly, they were out of luck but unlike Steve I will mention one of the new features, namely this cool widget (which is mentioned at the end of this video). That's right you can (well, will be able to) monitor all sorts of neat stuff about your Leopard server right in the Dashboard. You can monitor things like how many people are connected to the iChat server, or the processor usage in the past hour. This gives sysadmins a nice thumbnail view into the health of their servers.
Kudos to the Leopard server team!