Engadget’s Windows Phone 7 Series hands-on has a video walkthrough that shows off the daring and unique new user interface.
I really tried to watch with an open mind, but after using an iPhone for almost three years, it’s hard to not compare with my experience. While the interface aesthetic is creative, it looks like they have a long way to go in terms of interface engineering. (E.g. watch for how many times the demonstrator mis-taps.)