Windows 8, Windows 8 Pro, and Windows 8 RT were announced today.  Here’s an excerpt from the Windows Team blog:

“Today I would like to share information with you on the editions that will be available for "Windows 8" when it is released to market. We have talked about Windows 8 as Windows reimagined, from the chipset to the user experience. This also applies to the editions available – we have worked to make it easier for customers to know what edition will work best for them when they purchase a new Windows 8 PC or upgrade their existing PC.

Windows 8 has the flexibility you need - whether you’re on an x86/64 or a WOA PC. You can use a touch screen or a keyboard and mouse – and switch anytime. It’s beautiful, fast, and fluid design is perfect for a wide range of hardware. And you’ll love browsing through the Windows Store and downloading all the apps you want. And those apps can work together too so you can share photos, maps, contacts, links and whatever else you want faster and easier. All editions of Windows 8 offer a no-compromise experience.”

See the full announcement at http://windowsteamblog.com/windows/b/bloggingwindows/archive/2012/04/16/announcing-the-windows-8-editions.aspx.  Be sure and take a look at the feature chart comparison in the bottom of that blog post.