I think until discs are allowed for road, you may not see too many manufacturers switch to discs. Many customers for cross want a bike that they can dual purpose cross and road race/crit (if necessary). If a manufacturers full line up is in discs, they exclude this group - at least for now.
I can see cyclocross going mostly full discs sometime in the near future, but for now Canti's will be fine.
All great manufacturers are working on disk bikes for road. It's just a question of time when the pro riders are running races like the Tour de France with disk bikes.