There are a lot of cool things about the new Google Maps update, but a few features from the old app didn't make the jump. Google made a big deal about offline maps when it was added a few years ago. So it's a little surprising to see this feature missing in Maps v7... or is it? Mountain View has included a bit of an Easter Egg here.
If you want to cache an area for offline access, just go to that part in the app, then type "Ok Maps" in the search box.