According to Gamespot, they have received a tip from someone working at Take-Two Interactive. According to the person (who Gamespot will not reveal to the public), a release date for 2012 will be "pretty likely,".
Rockstar, has not declared if any of this is true or false. This should all be taken with a grain of salt, Gamespot is being really shady with this piece of news. They're not giving away any names and they're not giving much information either, so as of now this still counts a rumor.
Spotted via Gamespot