You do if you're flying, taking Amtrak, or driving. Otherwise, no.

The issue here isn't about needing ID (that's not new), it's about a new requirement for an enhanced ID, called "Real ID", in order to fly. Your regular old ID doesn't cut it anymore.

This is actually a softening of the requirement. Originally, they were saying that you simply couldn't fly after the cutoff date unless you had a Real ID or passport. But so many people haven't been willing to get a Real ID that they had to back off just a little.