Cellular News published an interesting short article suggesting that femtocell shipments will reach 36million in 2012, which in my view a rather conservative estimate. The estimate is contingent on a couple of big operators tidying up their messy business models. If operators grasp the big potential offered by the femto concept, then one can easily predict an estimate closer to 100 million plus. Nevertheless I perfectly understand why other experts do not see it this way.
An interesting quote in the article mentioned above:
"...no matter how attractive the service offerings a femtocell-based solution can bring, the sheer savings from backhaul and energy costs could equate to over $70 billion by 2012, outshining service revenues and providing enough financial incentive for carriers to actively support this solution".
Obviously, the operators that will gain the most are the ones that do not have yet a fully deployed 3G infrastructure.