I had the same problem, after I cleared all data from the Google Services Framework - which I did after reading an article that suggested that doing that might force the 4.2 update. I guess that disconnected the Play account, and some others - Chrome to Phone suddenly also stopped working.
To solve it, I opened up the "All" tab in app settings, and did clear data and force close on both Google Play Store and Google Play services. Then, after opening the Play Store on my Nexus, my Nexus also showed up again in my Google Play account in the desktop browser.
(Btw; clearing data on Google Services Framework didn't help towards getting the 4.2 update - and I got a feeling that I probably should not have done it)