Using Fibre really isnt anything new.. The UK backbones already use it. Problem comes with getting the fibre to the home.
I suppose if she has one direct link then it would be easy on fibre to fibre to get blisteringly fast speeds.
But the one thing that does occur to me - is that even with fiber there must be a limitation to the speed of data transfer... so therefore once you start bringing more people into the equasion surely some sort of congestion effect will kick in. We all cant have a one-2-one link with every single place you can download from.. and therefore there must be backhauls in place - which will be shared.
Then theres also such things as how quick the data can actually be processed by the PC anyhow - how fast can data be written to a disk?... and how fast can servers "serve up" the data. Crikey theres more than enough sites out there already that cant cope with todays "Maxdsl" speeds" as it is