I get the feeling Verizon is plannign to bring back unlimited data.. It seems unlikely that they would be adding unlimited data so easily to our plans otherwise. I mean, if they wanted to stop it, how hard would it be to send an email to all customer reps saying NO unlimtied data for new customers..
With the recent double data promotion and now this spate of unlimited additions, I think they feel their network is robust enough to handle the data, and are doing a stealth soft test of adding more people in with unlimited data.
With ATT now going full steam ahead on it's LTE network, Verizon loses the cachet of having the fastest network. Also, ATT's doing a good job with new phones. However, ATT will most likely not be able to offer unlimited data right now, since they're still rolling out LTE. If VZ waits for a couple of months, just till ATT is blanketing the nation with LTE marketing, and then VZ announces the return of unlimited data.. think of the hit to ATT.
From a financial standpoint, the marginal cost of unlimited data is very low, as compared to the revenue lost when a subscriber leaves. The network is affected if all users suddenly start hitting the tower at the same time, yes, but there are various models that can show how to deal with that issue. In most cases, limited or unlimited will not be the criteria; even if users with 4-6 GB data packs hit the tower at the same time, they will have issues. Worldwide, telcos have found that the people who really abuse their networks are a very small percentage, and can be easily dealt with on an individual basis.
Just my thoughts, but if you see big ads from VZ touting the return of unlimited.. you read it here first!