Allthough the AKL is very close to AK you can't walk or shouldn't walk because of the busses plus roadways don't have sidewalks...You would have to walk back out to entrance of AKL then down a road to first intersection then walk down a very busy Entrance to the AK along where many busses and cars are coming and going...Nope I wouldn't walk.
Unless another DIS'er knows about a walkway??? I have stayed there twice and didn't see a walkway.
I would believe that Disney would frown upon you walking from the AKL to the AK. It can't be more than a mile or two (5 minutes by bus), but for safety reasons, I wouldn't recommend it.