I'm having the same issue. I just unlocked the bootloader (but haven't rooted yet) which required a data wipe. Everything booted back up fine but now I have a bunch of preloaded apps that need updates but Google Play won't update them. They just act like they're downloading for a second and then one by one fail and go back to the list of apps that need updating.
Also, I just checked and I can't download new apps either. It says for example: "Angry Birds" could not be downloaded due to an error (920)
Surely this can't be due to unlocking the bootloader. I've flashed tons of ROMs to my old Galaxy Nexus and never run into anything like this. Maybe Google is having issues on their end at the moment?