Going by Japan dates:
Gen I: February 27, 1996 - November 21, 1999
3 years, 8 months, 25 days
Gen II: November 21, 1999 - November 21, 2002
3 years
Gen III: November 21, 2002 - September 28, 2006
3 years, 10 months, 7 days
Gen IV: September 28, 2006 - September 18, 2010
3 years, 11 months, 21 days
Gen V has lasted 2 years, 3 months, 6 days
Going off these numbers I'd say we are defintely gonna see some Gen VI info in 2013, but it might not come to Japan (at the earliest) till early 2014, with the US in fall 2014.
Though I'm hoping for a Wii U pokemon game more.