Rockstar has officially announced Grand Theft Auto 5 with a placeholder logo on its website. No details have been released so far, apart from the fancy logo which has a speculative design of the roman numeral "V" and an announcement trailer which will be released November 2, 2011.
We aren't even sure if it's being developed for the current gen consoles because if you remember correctly GTA IV was delayed on multiple occasions after the announcement at E3 2006 where Microsoft's Peter Moore rolled up his sleeve to reveal a GTA IV tattoo.