Actually I am seeing exactly the same thing.
And I'm actually passing AdView#loadAd the AdRequest that I constructed.
More to the point AdRequest#isTestDevice always returns false (at least for all real devices I have tried).
Ie
AdRequest adRequest = new AdRequest();
adRequest.addTestDevice("04C06F4F962B"); // Ideos Test Device
adRequest.addTestDevice("0149B3A11600E01D"); // Galaxy Nexus Test Device
Log.v(AppConstants.TAG, "(ads) isTestDevice=" + adRequest.isTestDevice(this));
admobAdView.loadAd(adRequest);
Always return false for #isTestDevice and always shows real ads.
This is using an Admob mediation id to construct the AdView.
William