Visit www.buildwindows.com to view Steve Sinofsky’s keynote at Anaheim, California and to download the Developer Preview.
From the official Windows 8 blog:
Many are interested in Windows 8 for ARM processors. Everything we showcased today at BUILD also runs on the ARM-based Windows PCs being created by ARM partners and PC manufacturers. Windows 8 running on ARM will ultimately be available with ARM-based hardware that you can purchase. ARM requires a deeper level of integrated engineering between hardware and software, as each ARM device is unique, and Windows allows this uniqueness to shine through. The new development tools enable you to start today to build Metro style applications that will seamlessly run on x86 (32 and 64 bit) or ARM architectures. Even if you use native C/C++ code, these tools will enable Metro style apps to target specific hardware if you choose. As new PCs become available for testing, PC manufacturers will develop seed programs for developers.
I’ll be posting screenshots soon