Interestingly, AT&T Inc. and Verizon Wireless, which led the charge into fixed-price plans, still have a huge, but diminishing, business in land-line phones. Dulaney said the switch to wireless-only subscribers makes sense to those companies, too.
"They're probably interested in moving people off land lines because they get more money per minute with wireless," he said. "In any case, they want to make sure they keep customers regardless of where they may be."
Trend 4: More voice and data bundling
Dulaney noted that flat-rate cellular plans play into another trend in the cellular industry: the increasing reliance of cellular operators on revenue from data plans.
"It dovetails into what we're seeing on the data side, where we're seeing unlimited data plans," Dulaney said. For instance, he said, customers can get an unlimited data plan for a BlackBerry for $45 a month.