As we see in this first ever video, the Windows Phone 7 interface is filled with simple, beautiful animations not so dissimilar to the Zune HD. UPDATE:
UPDATE: Here's more video showing us the experience of maps and web browsing. Very sharp.
UPDATE 2: And here's a full features rundown clip that's a must-watch.
UPDATE 3: One last video from Recombu—here we see a giant Windows 7 Series mockup running the interface in real time. It probably offers the best feel of general navigation we've seen yet.