I was talking this thread over last night with my GF/hiking partner and she reminded me of the rodent problem at many of the AT Shelters... So another point, if you can at all avoid it, which is fairly easy to do, try to camp at non desinated camping areas... It seems the rodent population of the AT has learned that humans mean food..
Be sure to make time for the scenic outlooks, much of the AT is in tree cover, so you often have to take detours to see the scenic outlooks..
And make time to talk to fellow hikers along the way, you'll learn all kinds of valuable information regarding trail conditions and tricks and tips for making your journey a little less daunting.