dakine makes some cool backpacks that have notebook sleves, i have been using one for about 2 years now and love it, they take alot of abuse and pad the laptop well. has held up to 2 snowboarding seasons also, so it takes abuse of all types, its also extremely water resistant, as long as you dont submerse it in water your stuff will stay dry.
http://www.dakine.com/street-series/guys/packs/