Windows 8: what and when?

What?
Well it is hard to say, but here are some links to some of its details like NUI, multi-touch support and some of its features:
- http://msftkitchen.com/2009/11/windows-8-more-roadmaps.html
- http://news.softpedia.com/news/Windows-8-NUI-Beyond-Multi-Touch-151125.shtml
- http://www.winsupersite.com/win7/win8_leak.asp

When?
According to different sources as early as Summer 2012

More about Windows 8 on MSFTKitchen: http://msftkitchen.com/category/windows/windows-8