It's called Broadband Over Power Line BPL.
http://www.arrl.org/news/stories/2004/03/18/100/?nc=1

Companies will be able to send you power, highspeed internet,
telephone and tv all in one package using the exsisting power grid
that is spread all across the country.

I'll cut straight to the pros and cons. Pay special attention to
the cons.

PROS:
-You can get 4 services on one cable: power, telephone, tv, and
highspeed internet access.
-Initially one lower bill to pay since all of the services are
bundled into one company.
-Less cables and wires to run and hook up.

CONS:
-BPL uses Radio Frequencies RF that jams frequencies that are used
by police, EMS, fire departments, rescue workers, military, some
government agencies, amateur radio frequencies, cordless phones, etc.
-RF at certain power levels can cause burns and other radiation
related afflictions in humans, wildlife and vegetation. Possibility
for causing wildfires exsists.
-Because all these services are bundled into one company it can make
for a monoply, which in the long run will not be good for the
consumer, effectively canceling out the second PRO listed above.
-For those that are paranoid: Highspeed internet access is always
on or activated. That is how it is today. But today it is only
connected to your computer. When BPL is put in place every
electrical device you have will be connected and anyone can gather
information about them and you. This also opens new doors for
hackers. If you have a security system connected to the BPL power
grid then it will literally open new doors for hackers. If you have
anything with a video camera or microphone connected to the BPL
power grid...
-THE BIGGEST CON OF THEM ALL
When BPL is put in place every single one of the cons listed above
will effect you even if you don't use BPL, EVEN IF YOU ARE OFF-THE-
GRID. CON 1 will effect the wireless communications of you and your
local public services, CON 2 will effect you physically, CON 3 will
effect your economy, CON 4 will effect your community... you do plan
on going into town don't you?

Visit the link I listed above for a better understanding of what is
coming. In some ways it is already here. Don't get me wrong I love
all the pros listed above, but not at the cost of all the cons.

When BPL is put in place every
electrical device you have will be connected and anyone can gather
information about them and you