Apparantly Zavvi leaked the release date.
' The European-based online retailer Zavvi.com has posted what appears to be a release date for Grand Theft Auto 5. When questioned, the retailer confirmed that the release date of November 23, 2012 was provided to them by their supplier.
"I can confirm that this is the release date forwarded by our supplier," said a spokesperson for Zavvi to Eurogamer PT. "If the release date changes, our website will be updated immediately."'
For me it feels a little too soon as they really haven't shown anything really... however GTA 4 was supposed to be released with a similar time but then was delayed into the next year so I suppose it could be true with a high chance of that happening again. All depends on how long they've been developing and if they fancied a change of pace with the marketing.