I watched the event live @web & I was speechless. Not just because it was something unseen so far (althought yes, noone expected it I'm sure!) , but because MS was constantly explaining how important are the customers and their wishes. And they were listening damn good all that time. As I said, I was left speechless. Whether the things will work as smooth as they were shown is another story, but here are the major points from my perspective:
1. Interface is expandable, e.g. each app can extend it (kind of live widgets + subsections for office, multimedia and games). Which means xda & modaco could also do smth to make things better I guess

In addition that means No more 10000+ application icons and thousand of screens with stupid applications, that have no clue about each other

Interoperability is the key word.
2. HW will be more or less the same - Huraa-finaly we might get video for skype, proper 3D games and many other nice things, reserved so far for the closed platforms. Although it was said there will be devs with different screens and +-keyboards.. It seems MS had made a round table with the HW manufacturers and they agreed on HW specs and timeplan! Impressive!
3. Multiple calendars support!!!!! Yes, finally! Agenda/Cal looks brilliant. The example shown was with 1 exchange and 1 push calendar..
4. Sync with exchange of course - viva la activesync (no, I don't believe they'll issue patches for exchange server to communicate with zune sw

)
5. Video & multimedia-I hope the codecs will be part of zune subsystem-can anyone bring some info what are the supported containers/codecs from zune hd?
6. social networking a-la sense style!
7.xbox live - I don't know if that means ported games from xbox - if that happens that would be...well, let's not dream for now
and much more...
But you know what - I can't stop laughing now, when I imagine Google and Apple! If they had any plans to present smth soon (similar like the current iphone or ipad) - I can only imagin how they throw it to the basket and re-call all the vacation plans for the next couple of month. I'm expecting their answer to today's MS presentation. Whoever resists to go into direction customer customization and contacts-internet integration will fail in my opinion. I see symbian, htc, samsung, android and now MS placing that as a central point of their marketing.
P.S. Motorola, Acer & LG were not shown as key partners, taken part of the pre-launch events..wonder if that means they're focusing on android from now on, or they will follow whatever they're given..
P.S.S Symbian^3 also looks in the right direction..I'd expect nokia to keep its fans on board!
P.S.S.S The word google was gently avoided all the time!

no coincident I believe! not that's important though