I agree completely with becka. You could do AK in a day or less but I don't recommend it if it is your first time visiting the park. AK is much different than the other parks. You need to go with a different mindset. The point is not to race from one attraction to the next. The point at AK is to realize that the entire park IS the attraction. Everywhere you turn, every path you take, every trail you explore has animals, carvings, scuptures, etc. If you go in commando mode you will miss so much of what AK has to offer. If you are following a path and you get to a fork in the road, take one side, then double back and check the other path. Don't assume they are the same - they're not. Heck, our first visit we probably spent at least 45 minutes in the queue area for ITTBAB. Not because it was crowded but because we were admiring and photographing all the animal carvings. We just let people pass us who were heading for the show.
I also think AK has a couple of the best shows on property: Lion King and Tarzan. These are both not to be missed.
If you are a nature/animal lover, you will find yourself spending a lot of time in this park. It is so unfortunate that the majority of guests just fail to appreciate this place and Disney has been forced to make changes to appeal to the more thrill-seeking people.
Ok, I'll get off my soapbox now.