The keywords of the day have to be "Ultralight Hiking".
One thing I got from this was that I should be able to get my kit to the 9kg or less range including the pack, which means a new pack. Will hit Mountain Designs or Macpac after work and see what's available.
Will also want to check out options for light weight devices. I have a first gen Air that comes in at 1.36kg. so say 1.7kg with the power adapter. Will also want a camera and gps, solar charger and a handful of rechargable batteries.
Flipside may be to dump the laptop and go with a tablet. Need something to document the journey though.