Most people I know barely benefit from gigabit Ethernet. Most people I know are not running Exchange servers and huge file sharing projects on their LANs but hosting their data on their local PC and using their network for E-mail and the web.
While 10-100Mbit made a huge difference to peoples' networking abilities, and going from that to gigabit helps with smooth transfers of larger files, there's still a lot of people running 100Mbit and quite happy with it because modern switches are pretty good at what they do.
Sure, as a geek, I'd love to have 1Tb/s streaming but its really not that relevant to most small business or home users.
For reference, at 12MB/s (100Mbit), you can transfer a 9GB DVD in about 12.5 minutes. At gigabit speeds, you can do it in just over one minute instead. Jumping up to 10GbE brings that down to around 7 seconds or so ... but why are you moving a 9GB DVD any faster than one minute? It takes longer than that to burn or watch.