I did my first MSDN webcast this morning (you can find details about it here). As promised I wanted to put in links to all of the demos that I did during the webcast. If you have any questions, please let me know. SDK samples are available in the \Program Files\Microsoft SDKs\Windows Workflow Foundation\Samples.zip. I usually just expand the zip file so that I have a samples subdirectory in that folder.
Special thanks to Vittorio Bertocci and Iwona Bialynicka-Birula for their work on the custom designer sample application.