A new addition to the granite gear range of sacks is out this spring, called the crown, it weighs less than 1 kg, uses a very durable and water resistant material, vented back panel, 60L. Not much in the way of bells and whistles, but looks great for the weight. Anyone looking for a new pack should consider waiting.
http://www.youtube.com/watch?v=7mDb4PKoD_Q