This is all pure conjecture, which is the best kind, but according to Bokardo, a site that covers social networking sites, Apple may be making a play in that space when Leopard hits the streets.
The most interesting idea is the Wiki server that will be embedded in Leopard, allowing teams to create and share live documents.
Leopard Server includes a Wiki Server to make it easy for teams to create and distribute information through their own shared Intranet website. For the first time, all members of a workgroup can easily create or edit content right from their browser. With a few clicks, or by dragging and dropping, they can upload files and images, track changes, assign keywords, hyper-link pages, view and contribute to shared calendars and blogs, and search for content on the group Intranet.
This is right in line with iWeb and the shared calendars in iCal. Then you’ve got team logins in the OS itself, potential social aspects to iTunes, and fancy new iChat integration along with picture-in-picture chatting.
Apple Making Huge Social Software Push? [Bokardo]