Alex O'Dwyer, a character animator at Rockstar Games, has an October 2012 release date listed for Grand Theft Auto V on his resume.

You can find O'Dwyer's LinkedIn account here, and his CV here, which contains the possible release date. This is by no means a confirmation of Grand Theft Auto V releasing in October, but it is a reasonable time frame for what will likely be one the biggest releases of the year, whatever year that may be. 

[via Joystiq]