Microsoft Research's Ken Hinckley has unveiled a prototype device based on two OQO Model 02s running together dubbed “Codex”. Hinckley believes it's the future for gadgets as dual-screen devices have become the subject of increasingly elaborate internet fantasies. Now, rumors about an Apple “Brick” device have stirred up dreams of future tablets, such as the alluring One Laptop Per Child v2.0 concept photos.
Nintendo invested in their dual screen gaming device the DS Lite which has become very popular in all markets. Dual screen computing is common in businesses and is known to increase productivity so perhaps a dual screen device isn't a bad idea for the future?
More info: Microsoft Research Blog