They are coming to road bikes. For example:
http://www.bikerumor.com/2012/04/20/...hifter-levers/
I can understand the OP worrying about the fad issue. A few years back I bought into Specialized's 24mm axle size. Meh. That sized died fast, and I'm stuck with a fork and front wheel that don't mesh with anything else on the market today.
Disk brakes are mainstream though. No worries at all there, imho.