Om has an interesting piece on a small startup working on a new optical technology for LANs/SANs. While I always find new optical gear interesting I have a hard time accepting that we'll ever see optical LANs. The optical folks always seem to forget the huge sunk cost of cabling in the walls. Anyone upgrading cabling these days is either using CAT5E or CAT6 copper. No one is considering fiber. It's too expensive and limits usability. No POE over fiber! What if the next great optical solution isn't 850nm or 1310nm compatible. We have a customer that has a whole building wired with fiber. It presents constant integration and support problems.
Really, I think Power Over Ethernet might be the most compelling reason for fiber not being in the LAN. VoIP is hot and getting hotter. Same with WiFi. Both utilize POE. With POE you can centralize power resources and manage those power requirements better. You can build one (or several) big UPS instead of having a UPS on every desk to provide power to that VoIP phone.
And with Gigabit Ethernet over copper, what's the compelling argument for fiber? How would someone benefit from utilizing .001% of their 10GE fiber connection instead of the 1% they currently utilize the 100BaseTX at?