I may be wrong but isn't BPL's implementation limited. Doesn't BPL
have a low enough bandwidth that it is only practical in rural areas
where it doesn't have to service to many customers from the same
power line?

Depends how they set it up.
Broadband on cable is limited too, but they do it as "neighborhoods", rather
than trying to feed the whole thing from the head end. I expect the power
companies will roll it out anywhere they have enough potential subscribers
to justify the cost.

http://www.arrl.org/news/stories/2003/08/08/2/?nc=1

I think this is at least one point, where hams and CB folks have solid
common cause.