There were a couple of interesting Windows Presentation Foundation bits I've seen recently.
A third-party called XCeed has released a DataGrid control for WPF that is free of charge! A DataGrid was conspicuously missing from the WPF toolbox and I think XCeed are on to a winner here. Click through the link for a demo (with source available) of the fully featured data-bound control - I am well impressed! Thanks to Tiernan for reminding me of this.
Also, a number of people including Karstenj have pointed out Doninoken, a short film done in WPF for the Japanese Vista launch by design agency Bascule. The aesthetic is created by cycling detailed texture maps on flat surfaces in 3D space - very reminiscent of cult favourite Parappa the Rapper. It's a great example of an aestetic that would be very difficult (perhaps impossible) to create without a full 3D engine.
And on an aesthetic note, sadly, I'm not going to be able to make it to Designertopia. Clare is going to be there though! So, bloggers -- I want a full report! :) I am off to Seattle for a conference and will try to bring back even more designer/developer info.