I (Jim) have been using the Windows 8 developer preview for most of my development for about a month now, and I have to say I really like it.
This is only the developer preview of course, available from Microsoft, its a pre-beta, so it isn't 100% stable but totally usable for somebody like me. I really like the new start screen, especially as a huge fan of Windows Phone, the whole 'Metro' UI as it's called it fantastic.
I am looking forward to trying to develop a full screen Metro app for WIndows 8, but will probably wait until a full beta is available, with the new Windows store.
I definitely recommend trying the developer preview though, and the latest developer version of Visual Studio, with all the tools to help make Metro apps, its the future people - embrace it!
