Just noticed this now on Android 4.2.2, I'm pretty sure the option to restrict background data per app was there a few days ago.
Now I can't stop the Play Store from using up my data. There is now a global "restrict data access" but it doesn't seem to apply to some apps - like the Play Store.
EDIT: weird, now they're back again. I think the only thing I did was log out (via
about:debug, then Setting -> Debug -> Reset prelogin, the last one)