Mix 08 seems to be much more mature than ever before. In previous years there were a lot of ideas being spoken about; this year there are much more implementations of those ideas available to look at. It seems like a lot of people have been working on the new technologies over the past year or so. Hopefully that will lead to the ripening of many technologies (especially WPF) to a point where we can actually use them.
As an example, there is a scheduling application available for Mix. Unfortunately it only runs on Vista, but I captured a video and made a few screenshots for you.
This is the opening screen, with an agenda for the 4 days of the event:
(Click the image to make it larger.)