Apple's new Mountain Lion Server can be thought of as a new, improved version of Lion Server, but one that continues to shift away from enterprise uses and towards workgroup and even home use. OS X Server 10.8 brings more functionality to its simpler Server app, but drops the advanced GUI administration tools of Server Admin, as well as and some features, most notably Podcast Producer has also been dropped. But the surprise release of Workgroup Manager 10.8 restores some advanced administration features thought to have been deleted.
Overall, OS X Server 10.8 is an improvement in Lion Server. The new version of the Server app adds the ability to configure DNS, FTP, NetInstall/NetBoot, Open Directory, Software Update. DNS and Open Directory are particularly welcome since are required services for many owners of OS X Server in certain situations. The DNS pane of the Server app is easier to use than the corresponding area of the old Server Admin, without much loss of functionality. Lion Server completely eliminated the GUI for FTP, making it a command-line-only option. Mountain Lion Server restores graphical FTP management in the Server app. NetImage, Directory Utility, and Xsan Admin exist largely as in previous versions, but now accessed through the Tools menu of the Server App.

On July 25, Apple re-released Workgroup Manger, the tool for advanced administration of Open Directory user and group accounts. Most observers had thought that Apple had dropped Workgroup Manager, and numerous reports of around the web had said that Workgroup Manager had not been available to developers during the beta period. The same had been thought of Managed Preferences (MCX) feature had been eliminated. Although the Profile Manager provides many of the same client management features of Managed Preferences, only the later works with Mac clients running Snow Leopard or Leopard. Workgroup Manager also lets you create computer accounts and computer groups of Macs for purposes of client management.
Profile Manager is still the better tool for configuring and managing Mac clients running Lion and later, as well as iOS devices. Profile Manager hasn't changed much from the Lion Server version. Profile Manager lets you create settings and group policies for clients via configurations profiles, which it can use to automatically configure to your Macs and iOS devices. You can also push out updated settings automatically with the server's push notifications certificate enabled.
Apple axed Podcast Producer, the audio/video workflow package, from Mountain Lion Server. Apple also removed Xgrid, a service that enabled you to farm out processing tasks, such as Podcast Producer video encoding, to multiple Macs on the network. With the removal of the Server Admin tool, Apple removed the ability to create advanced settings for the email server. The version of Server Admin in Snow Leopard Server certain provided access to a lot more settings, but Mountain Lion Server doesn't lose much compared to Lion Server.
Apple removed NAT (network address translation) from Mountain Lion Server, which means you'll need a router in between the Mac and the Internet. Other network services -- DHCP and the firewall - are gone from the Server app, but didn't disappear. You now have to set them from the base OS X System Preferences. There are far fewer firewall settings in System Preferences, however, than were available in previous versions of OS X Server. For instance, you can only change port settings from the command line interface in Terminal.
OS X Mountain Lion Server is available for $20 from the Mac App Store. It requires the Mountain Lion base OS X ($20) to be installed. The Mountain Lion client is 4.34 GB download. For DSL users (such as subscribers to AT&T's U-verse in San Francisco), Mountain Lion can be a 6-to-8-hour download.