My app uses maps v2, and has been working great. My device has the latest version of Google Play Services. And the SDK Manager shows Rev 11 for the library. I updated to adt 22.
Ha, got it. Issue was related to updating, but I hadn't updated the tools in a while, so Rev11 of google play services is no good. See this bug
In short, rev 11 requires a version of the app not yet released, and google had pulled it, and I didn't realize that. So, in case anybody else hits this: