I've released a new version of WPF Contrib (October 2008, although it's released in November. I changed the release name a few times, so I decided to leave it like that. I'm only late by a few days. 
It contains quite a few fixes and new features. Read about it in the project wiki. There are some breaking changes, which, unlike Microsoft, I can easily make, since I don't really have a huge user base. Although, many of the new features in TaskDialog were motivated by user requests. Many of the new controls and classes already appeared in articles in this blog.
I've also set up an XBAP demo (only for features that work in partial trust):
http://arbel.net/wpfcontrib/AvalonLibraryTestBrowser.xbap
As always, I would like to hear from you if you have suggestions and bugs.
If you enjoyed this article, please consider sharing it!
Feature Request :
this is very similar to autogrid, or possibly the stackcolumn control.
Basically I want either an AutoGrid that can dynamically create additional columns based on resize, or a WrapPanel that snaps controls into columns/tabstops
Let me know if you think this is possible.
Jason Coyne
gaijin42@gmail.com