I've seen WP7 and played with it a little. It's okay. It's a more fluid webOS 1.3, really. WP7 is still missing many key features/apps, and I'm not too impressed with the interface (actually, I hate it)
Multitasking or even task switching = Not yet
Flash Player = Not yet
Copy/Paste = Not yet
Windows Live Messenger = Not yet
That said, even Microsoft understood the need for freaking voice commands and mic APIs! It's utterly ******** we don't have that feature on legacy webOS devices.