News about these new ultrabooks have been around for a while:
http://ultrabooknews.com/

The weight isn't groundbraking. They're all 1.1-1.4kg (2.4-3lb), and companies have produced or are offering now much lighter laptops with a decent computing power. Two examples:

http://www.genesi-usa.com
http://liliputing.com/2011/10/who-ne...-2-pounds.html