Now that I think about it, it's since 2000 that I don't have a fixed telephone line in the house where I live. Cell phone and ADSL or 3G data connection meant to replace it (with some limitations in terms of service availability and emergency calling).
It's probably a known trend: in the US 20% of people have made the same choice.
And look how many families are adopting wireless phone services only! I'll write on this topic and on interesting solutions.
VOIPBLOG.IT reported it in Italian.