That phone is really cool ..I've worked at phone company doing internet support (up until recently of course) for over 7 years. I can tell you that the phone network has a number of advantages over other systems. Primarily due to heavy regulation on the POTS network.

Bear in mind cell/VOIP do not have these same prequisites:

1) All lines, whether in service or not must be able to dial 911.
2) 911 service takes priority over ALL OTHERS (to the best of my knowledge, it's numero uno lest there be heavy fees to the company involved)
3) Voice repair takes priority over internet repair (same).
4) VOIP 911 is not the same as POTS 911 - look it up.
5) POTS lines will frequently work in an emergency if the power goes out (all run by gigantic backup generators, usually at least 700hp diesel for a small community) - at least until the telco runs out of fuel for the generator.

Not to say copper wire networks are foolproof and faultless - far from it. But at least you know that on the by and whole if you need to dial 911, you can. At the end of the day though, it's a dead system. I personally use VOIP at home, but at least understand the benefits of a good old POTS line. Which is why I have a separate line hooked up (not in service) for 911 calls.