Through he doesn't seem to offer any truly new information, Daniel Eran over at Roughly Drafted has a nice post summarizing the changes coming in Leopard Server. One of the most significant highlights is the addition of many more "collaborative services" including a new iChat server that relays messages to the outside world, an iCal server for calendar sharing, a wiki server, and the Podcast Producer for automated podcast publishing. It seems like Apple is finally starting to ramp up OS X to be a stronger competitor to Microsoft's Exchange server for sharing information across a workgroup. While it's true that OS X Server probably isn't on the radar for most home users, it's good to know that Apple is continuing to refine our favorite OS for running on sweet Xserve iron, or maybe even a Mac mini home server.
[Edit: removed last sentence about pricing. Apparently, I misunderstood the way it works]