It will never happen until/unless there is ever an overabundance of capacity and the competitive environment drives down prices.
Right, and I would assume that any family data plan would be more like it is today for minutes. There isn't a Jim's Calling plan where you are charged for your group usage in batches of say, 100 minutes, you have buy a bucket of 700, 1400 minutes etc, and the overage charges are expensive, so you are encouraged to buy too much just to be safe. So I would expect say 6GB, 10GB, 15GB family data plans, priced "appropriately", i.e. for VZ rather than for consumers!