I called Disney today and was assured that if you buy the AP's at the gate, they are not active until you enter the park for the first time. I gave her the scenario of going to pick them up tomorrow, and not going into the parks until March, and she said that they would expire March 2016.
She said it is on the website, and this is the official policy. As long as it is not an upgrade on a used ticket, the pass is 'dormant' until activated at the park turnstiles, kind of like the vouchers that are available from third party vendors.
I'm probably going to drive to
Disneyland in the morning (335 mi one way!) to buy the passes and go for the day with a comp ticket that expires soon. I'm banking on the prices increasing before we take our trip in March (looking increasingly likely), and now that they don't allow gift cards to buy passes online, I need to go to the booth. Combine this with the lower gas prices, and it will be a savings of $200-$400 depending on the increase, plus I am going to the parks tomorrow.
Am I safe to assume I can purchase annual passes for people who are not present at the booths? I will be going by myself.