Grand Theft Auto 5 will be released this autumn, according to a 2012 release schedule from a major UK High Street retailer obtained by MCV. General opinion is that GTA 5 will be released in 2013, but Rockstar may want to ensure the game's launch on current generation hardware isn't hampered by an imminent arrival of the next Xbox. In addition, the 2012 release schedule also reveals both The Dark Knight Rises and Battlefield Evolved.
This should be taken with a pinch of salt! However previous GTA games (III/VC/SA/LCS/VCS) where released in October! I personally think that it will be announced for October but then delayed until March-May 2013 R* always delay their games!