We're continuing to update UDN based on your feedback.
We've made many additional documents public, including
The FaceFX docs linked in http://udn.epicgames.com/Three/FaceFX.html
and more I'm forgetting.
We've also made more improvements to the search functionality, and improved top down organization, with many more documents linked from
and the new
We're also working on a more in depth "getting started" tutorial. Please tell us what additional documentation you'd like made available.