1) You obviously have to pay extreme roaming prices. And it does not matter if it is a call over your own provider. They will see to it that you pay extra and a lot extra. As they are flying all other pricing regulations will be deemed void, regardless that other places are not allowed to do the same, because they are on the ground (e.g. no roaming cost or blocking in malls or conference centers)
2) If you want to book a seat where you can do calls, you need to book extra
3) If you want to book a seat where people are not calling, you need to pay extra
4) To pay for the systems to be installed, prices will increase to pay for it, regardless if you use it or not or if it is even needed or not.
5) You will be spammed 10 minutes after you get in the plane.
OK, 4 and 5 might be a bit over the tom but 1, 2 and 3 are things I could see happening.