I think the cost to consumers to churn, especially smartphone customers, is really high so it will take more than an all-you-can-eat data plan at a competitor option to make most people switch.

Also, i wonder how many "new" customers to MVNOs are just getting a second phone for personal use, a side business, etc. Given that the TIA is predicting 110 percent wireless penetration in the US by 2015, it seems there will be enough room for dozens of different approaches to data pricing.

You make a really good point, but consumers also have more options than before. I think if AT&T and Verizon keep making data pricing changes like they have, their customers may start to look more seriously at Sprint (as long as it keeps unlimited), T-Mobile and maybe even these new MVNOs that are launching now.

Correct. I think investors are the key constituent for publicly-held telcos. 

Investors want to see growth even in saturated markets. The only way to get growth out of a relatively fixed subscriber base is the jack around with fees, broadband charges and pricing.

Interestingly, policy and charging changes can help increase average revenue per user (for the most data-hungry users) while helping other customers pay less for using less.

So I think the formulas will keep changing and consumers will have to be more vocal about what is working and what's not.

AT&T and Verizon are hardly hurting revenue-wise now are they? I can see people grumbling on the boards every day about the ever-changing plans and caps. Do the big two have such a captive audience that they can constantly push up prices? Will people stand for it?