Washington State friends: eeek! Make sure you passport is current. "there still will be 120 days notice before the TSA no longer accepts their IDs." But do you really want to be caught out by that? I thought not.
Mass readers: should be okay through leaf peeping season; continue to monitor developments.
You would _think_ that everyone would have fallen into line by now, but, alas, no.
Also, apparently there will be less free access to Pre-Check, so if you haven't signed up for that, you might want to.
ETA: Today, January 8, the Department of Homeland Security has extended the deadline.
"The Department of Homeland Security has given states an extra two years to comply with federal requirements to issue driving licenses with extra safety features, meaning that residents of noncompliant states will have until January 2018 before having to use a passport or other official identification to board a domestic flight."
Washington State readers have a choice I was unaware of when I first posted. You can pay $3 per remaining year on your driver's license or state id to upgrade it from "standard" to "enhanced". The enhanced license or ID is Real ID compliant.
Here is a little about Enhanced licenses and IDs:
Unhelpfully, this page does not list which states issue them. This one, however, does: