Metro is revolutionary. It's not just a pretty skin. It's a completely different philosophy on how to present and handle mobile ecosystems.
We now have an OS that is task centric as opposed to app centric.
It will take time for people to grasp that I guess. They've been trained to measure everything by Apple's standards and don't really think outside of the box.
What is the big difference, really?
People want to DO things, I dont think HOW really matters. And compared to iOS and Android there is still so much you can do on those platforms that you can not on WP.
But I hope WP8 will change that a bit.