I had a look at the interface and the functionality , and I have to agree, there's nothing like it at the moment - I guess with their backs to wall, MS had to actually 'innovate'!!!
But yeah, it's miles ahead of IOSAndroidSybian - [you may aswell group them all together, afterall they're all derivatives of each other - and these OS' are looking decidedly dated now ] - Someone way back in the 80's/90's (god knows who - Nokia?) decided to copy the icon based - one-function per app model from the desktop pc and cart it to a mobile device. Bizarrely - this model has not evolved, yet alone been superseded!
The thing is, a mobile device is not a desktop pc - what the user requires out of a PC is different from a mobile. The same goes with it's functionality, due to the constraints of the hardware and software (e.g. physical screen size and dimensions, processor, memory, battery etc)
I think MS realised that what you want and expect from a pc is different on a phone - this in turn led to it's complete rethink of how a mobile OS and interface should function. I applaud this.