My wife is a service rep at AT&T. She informed me that AT&T is offering double data on Datashare plans 15GB or over.
So instead of 15GB of data, you'd get 30GB for the same price.
On the datashare plans, all users/devices on the plan share the data from one pool (no limit per phone).
The price and data are good until you change the plan. You have to sign up by October 31, 2014.
http://www.att.com/shop/wireless/dat...id=F4T6xfvgpnW (scroll to the middle under "Mobile Share Value Pricing").
A family of four would pay $130 for the 15GB plan (which jumps to 30) plus $15 for each non-contract phone or $40 for a contract phone. Data-enabled devices are $10 (e.g. tablets with 4g).
E.g. Four brand new contract phones would be $250. If you decided to split it equally, that's 7 1/4 GB per phone. You don't have to split it so if you are a heavy user and the others aren't, you could use it all without suffering an overage.