My iPod touch (3rd generation) also seems to use pogo pins. I got a toothpick and played around with the contacts to see if they buckle. (Would be nice if someone could confirm that.) The headphone jack also looks otherwise exactly the same. (The iPod touch has, like the iPad 2, tapered edges.)
All headphone contacts buckle, and that's not enough to determine whether they're cantilever or pogo pins. The biggest difference I've seen in Apple jacks is that in their cantilever design the pins alternate from one side to another, while their pogo pin patent shows all the pins on one side.
Can anyone who has access to an iPad 2 look inside the jack and see whether they're alternating or not? I could absolutely be wrong with my assessment based on the few photographs I found online prior to the iPad's availability.
I'd also be very interested to see a photo of what a headphone plug looks like plugged in to the jack, to see how much of the ground pin is still exposed by the tapering.
