[Mr. Maggot]

Your standard computer hardware has a network card which supports a maximum of 100mbps. You would need a card upgrade just to be able to utilize such speeds.
I am going to look at the upper-limit of 1GBps with a skeptical eye. Unless ISP's out there are unbelievably good,(which I know they are not) its really hard to believe the feasibility of this happening anytime soon.
From my knowledge technical environments make use of Gigabit lines. So if such speeds are made available commercially they will cost a great deal.