I believe it was 2009 when the majority of homes were without landlines. It was something like 43% still had them. I think it was Fox or ABC reporting the information, you can google it and find it. The importanat number was the percentage of homes that were dropping them, it was huge. In my opinion, the number of homes that will have landlines in 5 years will be very small. With cell phones and VOIP, the fees for a landline just do not make sense. In some cases people must have a landline for business or if they have bad reception where they live.
I would like to hear from the installers of the percentage of people who they see that do and do not have landlines and their location because the regions do make a difference as someone earlier replied.