2GB/s vs 10GB/s is not the killer of the copper depending on what is true about distance is a problem.
http://www.zdnet.com/blog/storage/why-light-peak-will-run-on-copper/1216
If this article is correct about cable length max = 2 meters if copper the system loses a lot of value. pulled from above link
" Distance. = Glass FC is specd for 10,000 meters. Twisted pair FC for 33 meters.
Speed. = Glass FC currently supports 8 GB/sec, while copper maxes out at 2 GB/sec.
EMI. = Electro-Magnetic Interference is a growing problem with high-speed signalling. USB 3.0 is at the ragged edge of acceptable EMI today - and standards may get stricter. Glass is cleaner and much harder to tap as well."
He then goes on to say:
"The Storage Bits take
Given Light Peaks purported 10 Gb/sec speed, copper Light Peak will be lucky to support a 2 meter cable - plenty for notebook users - the same as copper eSATA. In a docking configuration, the dock could have optical transceivers for plugging into high-performance remote storage."
I am guessing his reduction from 33 meters down to 2 meters is his educated opinion that EMI will not allow a clean signal up to the 33 meter max length that is spec for twisted pair copper.
If you have this setup of light peak to be able to run 50 or 100 feet with fibercable allows large hdd rooms.
Never mind 10000 meters Lots of companies would love a light peak that travels 100 feet. I have the issue now that I have a limit to my hdds. My computer room can only house a pair of 8 bay units. I have a second room that can house 10 or 15 8 bay units but esata does not like to run 25 feet. Light peak would be a nice solution but at 2 meters oh well.