The Samsung tablet running the Windows 8 Developer Preview that Microsoft gave out to BUILD 2011 attendees is on eBay and other classified sites for over a thousand dollars, but if you want to experience Windows 8's interface on a tablet instead of with a keyboard and mouse, ExtremeTech has a guide to building your own with easily available tablets that you can buy anywhere at more modest prices.
Photo by Odi Kosmatos.
Essentially, almost any tablet on the market running Windows 7 now will do the trick, although ExtremeTech has some specific suggestions for tablets you may want that will offer the right balance of price to performance once you install Windows 8. The steps to installing Windows 8 on a tablet are similar to installing Windows 8 on a laptop without an optical drive, but you'll also need an ISO mounting utility to get the install going. Once you're finished, you'll have your own Windows 8 tablet, and you don't have to complain about how the Metro UI interface is designed for touch-screens: you'll be able to try it yourself.
How to Build Your Own Windows 8 Developer Preview Tablet [ExtremeTech]