identityservicesd

Yes, I'm still seeing this in the GM.

In my case it seemed to be related to restoring Messages.app preferences from a Time Machine backup, i deleted all the Messages/imservice/ichat/imessage/identityserviced Preferences,the com.apple.iChat container and ~/Library/Messages, logged out of iCloud, rebooted and started Messages.app, restored only the ~/Library/Messages/ folder and rebooted again, and then added my accounts back into Messages.app.

It also seemed to pop up when an iPhone with SMS Forwarding connected via bluetooth, i reauthorized SMS Forwarding and i hope it works now...