A number of network operators are already selling femtocells today to their subscribers to improve their 3G network coverage at home these days. All of them so far offer it as a standalone box with its own power supply and its own space requirements. A shortcoming of this is that when connected via Ethernet to a DSL or cable modem not supplied by the same network operator, it's usually not possible to prefer IP packets to and from the femto box to ensure quality of service.
But things are evolving and Lightreading now reports that fixed/mobile network operator SFR will shortly launch a new home gateway (combination of DSL/Wi-Fi/TV/fixed line phone box) that has a slot that can hold a femto card. I've been waiting to see news of this approach making it to the market for quite some time now and I think it will help to bring femto deployment to a whole new level. No additional box, no 'visible' extra transmitter, no 'visible' additioanl power requirements, easier installation, QoS can be ensured as the femto is now part of the access device at home.