Microsoft just announced a lot of new information and demonstrated the next generation of Windows for the first time in the BUILD2011 conference which is a new event that shows modern hardware and software developers how to take advantage of the future of Windows.
Go to channel9 to Watch the sessions and keynotes and have a sneak preview at the future of windows and windows development.
In order to start experimenting with the metro style app development, download the The Windows Developer Preview, which is a pre-beta version of Windows 8 for developers.
Go to the Windows Developer Preview downloads and download the installation that comes with the developer tools and start learning.
If you are having difficulties running the Windows 8 Developer Preview, check out Scott Hanselman’s post on Installing and Booting Windows 8 Developer Preview off a VHD (Virtual Hard Disk)