I spotted these on my walk to work Friday. When I took this picture the North (Northwest, geographically) side of Brannan Street between 7th and 8th was dotted along half its length by the poles you see, while the other half had fresh holes drilled in the concrete. This entire block now has the poles which, based on their height and spacing, seem to be harbingers of parking meters to come.
The meter heads are up and running as of Friday morning. A woman was performing some work on them as I walked past that day. She let out a contented chuckle when I called out, "Hooray, new parking meters!" I doubt she gets much encouragement from the public at her job.