It's solid - I'm not sure what everyone is going on about saying it's the world's most terrible UI. I didn't require any instruction at all figuring it out - it's mostly pretty intuitive. Some weird corners and quirks, but that's MS for ya. There are some cool tricks with the software keyboard that even the iPhone doesn't have.
That being said, an iPhone killer it is not. It's more responsive than most Android devices, but the fit and finish isn't quite there to really go toe to toe with the iPhone. It's also missing some pretty key functionality that is now common in the market (read: multitasking).
Also, its chief advantage here seems to be responsiveness. It's bloody fast, and that's a good thing... but it seems that a lot of the speed comes from first party apps being written in native code. Third party apps will be 100% .NET, and it remains to be seen if the same speedy user experience can be maintained in the third party realm.
[edit] The unified contacts thing in WP7 is really cool, and something I wish Apple would copy (but they probably won't). Having the phone be able to unify my friend's twitter, facebook, and address book entries is pretty slick.
I know, webOS had it first ;) It was cool then, it's still cool now, and I wonder why Android and iPhone haven't gone in this direction at all.
I think 3rd party app performance is going to be less about the runtime and more about how well it is coded. The raw perf difference between native and silverlight for something like UI is negligible.
Certainly for UI or high-level logic it's not going to make a big difference... but my impression is that there won't be any native code allowed, which is a stark contrast to both iPhone and Android.
If I need to write some performance-intensive bits of code, I won't be able to on WP7. Lots of the more novel/intensive applications (e.g., real time image analysis from your camera) will not be possible, or at least will suffer a significant usability hit compared to their speedier Apple/Google counterparts.
It's solid - I'm not sure what everyone is going on about saying it's the world's most terrible UI. I didn't require any instruction at all figuring it out - it's mostly pretty intuitive. Some weird corners and quirks, but that's MS for ya. There are some cool tricks with the software keyboard that even the iPhone doesn't have.
That being said, an iPhone killer it is not. It's more responsive than most Android devices, but the fit and finish isn't quite there to really go toe to toe with the iPhone. It's also missing some pretty key functionality that is now common in the market (read: multitasking).
Also, its chief advantage here seems to be responsiveness. It's bloody fast, and that's a good thing... but it seems that a lot of the speed comes from first party apps being written in native code. Third party apps will be 100% .NET, and it remains to be seen if the same speedy user experience can be maintained in the third party realm.
[edit] The unified contacts thing in WP7 is really cool, and something I wish Apple would copy (but they probably won't). Having the phone be able to unify my friend's twitter, facebook, and address book entries is pretty slick.
I know, webOS had it first ;) It was cool then, it's still cool now, and I wonder why Android and iPhone haven't gone in this direction at all.