Well, I have placed the femtocell at a greater distance from the router - but given the limitations of where to put routers and the length of cables this is still not an ideal scenario, I would say.
I was talking to an executive from Nokia Siemens about this yesterday, and he said the spectrum filters in current femtocells are still quite poor and really need to be further refined - although this would make them more expensive initially.
I'm no engineer, but as a consumer my view is that it's not good enough to just ask consumers to locate a femtocell six feet away from their router. Sometimes that's just not always that feasible, and it's hardly user friendly. It might be OK for the early adopters to do this - but what about the mass market? I can't help but think that if femtos are to take off as a mass-market solution for indoor coverage or even data offloading then these interference issues need to be eliminated. I'm just trialling a femtocell; not sure I would buy one just yet.