I'd heard this was coming but cynically I expected it to just be an Android in a fancy frock. Seems I was wrong, it is some kind of descendant of Nokia's own OS, albeit with some possibly worrying interventions from Microsoft, if I understand right.
It would certainly overcome some of the things I dislike about modern smartphones. A proper tactile keypad for example, that doesn't vanish with the screensaver, or disappear behind another window. And a battery that'll see me through a few weeks. A nice easy 'answer button' rather than annoying swipe gestures that often don't work.
Then again, there's a new iPhone due out soon too, which will remind me of all the things I do like about modern smartphones.