I can see the cellular companies going to a flat rate, like Metro PCS, to compete with the VoIP companies. Just like you have $15-$20/month fees for Sprint Vision/PowerVision services, evolution will cause them to include more services like MyCircle or Fav Five. Its coming, but they will do what they can to curb that wave.
That's how most things seem to evolve over time. It happened with local calls then long distance and then the Internet. It's probably just a matter of time.
The interesting thing is that flat rate pricing actually is very inefficient- it winds up costing the average user much more in the long term. ATT studied the pee out of it in regards to local calls, long distance, and then Internet. (The NEW ATT nee cingular/sbc probably has studied it too about cell phones).
What they found time and again is that 10% of the users use 90% of the network. Since these company's are for profit that means that 90% of us pay too much to subsidize the 10% who go hog wild.
The other issue is it creates wasteful usage and forces overbuilding of the network. Sort of like we all get nights and weekends free- because the networks are built strong enough to handle the daytime volume- they basically sit fallow over the weekend and since the incremental cost to service each call is like nothing they toss in free nights and weekends. So the current network is built to handle weekday volume. If everyone went to unlimited then a significant amount of people would use even more daytime calls - they might ditch land lines- and would have no fear of going over their allotted minutes. So the providers would need to build up their networks some more to handle that (remember the debacle when AOL went to unlimited how they had to quickly build up their network to handle all the additional usage and busy signal's were the norms for months and months?)- so who's going to pay for that huge build up needed for the network- VZ, ATT, sprint? Nope the users. And again 90% of us will over pay for he 10% hogs. So it's a double whammy for most- so be carefull of what you wish for.
I'm not sure of cell costs- but those same studies show that the price of landline phone calls over time basically dropped in a linear fashion as technology and efficiency's increased. So i'd imagine the same is happening with cell calls. When you go flat rate pricing the linear drop sort of stabilizes and that's the end of it. How much has anyone's unlimited dial up dropped since AOL forced the market to unlimited years ago? Most went up since then- no?