I'm in the pre-launch stage of a project called Glossa Technologia. GT is a collaboratively authored annotated bibliography of sources about rhet/comp and technology, and it's built on the open-source MediaWiki platform. In addition to open-source technology, the site is also open content, licensed under version 3.0 of CC's "Attribution-Noncommercial-Share Alike" license. (Incidentally, a write-up of the project will be included in the forthcoming edited collection Wiki Writing.)
As we tinker with the site, a couple of areas of attention are obvious to us, and we're contemplating just how to address them. One is structural: we'd like the architecture to accommodate different points-of-entry to the contents: author/title indices, topical categories, tag cloud, random page... structuring the content poses some problems in this area. For instance, what sort of formatting templates should we employ to ensure uniformity across entries? The second issue is more promotional: how can we make a site that's sustainable, sticky, and ultimately a useful resource for visitors? The first one to answer successfully these questions for me will receive a lifetime of unwavering gratitude. :)