Today (November 2, 2014) I visited the Verizon store in the West Farms Mall in Connecticut and attempted to get a Verizon SIM for my apple iPad Air 2. The clerk went in the back, talked to his manager, and came out and explained to me that since I purchased my iPad direct from Apple, Verizon cannot support it.
I had been using Verizon for several years on my iPad 3. As I wanted to retire that machine, and I was told I was unable to continue using Verizon on my new hardware, I cancelled my $20 per month data plan. I came home and signed up for T-Mobile on the iPad itself.
Later, I google searched and found this thread. It seemed inconceivable that Verizon could not provide a SIM for the iPad Air 2 unless they had sold it. The iPad is unlocked; it should work with any carrier as long as the carrier provides the SIM and wants it to work. I understand this, but I am not an expert and I did not want to argue with the staff at Verizon, so I just switched.
Verizon needs to do a better job educating its sales staff or they are going to lose a lot of business. They have the best network, but it is of little help if they turn away customers when they show up in their store looking to buy.