Sure, they're changing the paradigm, but it works. Half the reason they're releasing it this early must be so people can get used to it. Think about this, what do you do on your desktop PC? For most people, a lot of that stuff is on the web. I check Facebook, my Gmail/Hotmail, the news, the weather, stock price and of course all of my favourite other sites etc. Why should I have to manually search for this stuff every time? I'd much rather see all that stuff on my start screen, right there.

For your favourite sites, you can pin them. So, right there on your start screen will be an ATK icon . For things like news, there'll be apps, so without even going to a website, I'll be able to see what the latest news is on a live tile. If I want more, I click it. Of course though, the Metro-style interface isn't ideal for all desktop use, which is why the normal desktop is there. It's just as it was before, but better with a LOT more functionality, polish and performance tweaks. So I can play my Steam games, write my uni dissertation on Word and create a website on Dreamweaver just like usual.

One thing I really like is being able to effectively have a mini version of an app open on my screen. So whilst using Word on the desktop, I can have my mini email app open on the right. Anything comes in, I can easily deal with it. Apps are designed to work great in this mini view, compared to normal mail applications/the web which only really looks great when you at least have 800px width of it.

All that said, there are obviously other things they can do to improve, but it is only a preview after all. There's a pretty good demo of it all here (skip to 3:38 for the keyboard/mouse bit):