Femtocells and Personal Base Stations
The key issue with femtocell adoption is the interference with macro base stations and with other femtocells. Additional capabilities will need to be installed with the femotcells to prevent this.
Femtocells are commercially available in Japan and are in trials throughout the US by most of the carriers. In the west, Femtocells are seeing cautious acceptance. In this post the author watches in horror as 3G dongles gain acceptance over femtocells in spite of high costs and limited bandwidth.
For all things Femtocell related check out this website.