So after you have a non-smiling photo on file, you just have to go through the rest of your life with a huge, toothy grin--or at least when you're committing a crime.
Facial recognition software is intended to do two things: positive matching to ensure that the person renewing a license is the person looks like whoever is "on file", and mass matching to identify if someone if trying to obtain two licenses with different names.
It doesn't work very well on surveillance video, due to adjustments in the angle of the cameras; it was tried during a Miami Super Bowl once. Indeed, it doesn't perform very well even in laboratory conditions, and I would imagine that significant aging or intentional sabotage could cause unexpected results.
I would refer to Bruce Schneier, a respected security expert who has a lot to say on the (in)security of biometrics (and the credentials to back it up).
An important phrase to think about here is "give it time".
Consider for a moment how utterly unfathomable Project Natal would have been even as recently as a few years ago, and yet it is slated to be released as an add-on for a consumer gadget.
I'd say that could pass for surprised terror as well as exhuberance.
I can assure you that California is not forward looking, I just had my license photo taken and was told to smile.
Given the kind of future being looked forward at, yay for California.
The worst bit is that the UK government seems to think that storing our biometric details will somehow stop themselves leaving CDs full of personal information lying around on public bench seats.