Which is my pointer to a couple of write-ups that we've done over on All About Windows Phone which will hopefully be of interest.
The first was covering Microsoft VP Joe Belfiore's talk on the origins of, and the thought behind, Windows Phone's UI. However much a hardened Symbian or MeeGo fan you are, this is still worth a scan over, I was genuinely impressed by some of the thinking.
The second talk was by Marko Ahtisaari, Senior VP of Design at Nokia, and Albert Shum, General Manager of the Windows Phone Design Studio, looking at the coming together of Nokia and Microsoft in terms of design goals. Also, well worth a read, to give you more background on the thinking behind the Lumia 800 and the challenges of two very different companies working together.
And, please, no flames in the comments. We found the talks genuinely interesting - if they're of no relevance to you, just move on...!