A bit of frivolous arithmetic: Fallout: New Vegas hit shelves in 2010, so if Hines is on the money with his "six or seven years" thing, we can expect the next Fallout before 2017. Excellent.
Ah but, Obsidian did that one, surely we should use Fallout 3 in 2008, or Skyrims 2011 release to compare dates that mean nothing? And throw in Oblivion 2006. Then we can say it takes 2-3 years to release a game from Bethesda, whilst assuming they have half teams doing expansions and stuff. So 2014 at the latest, you can quote me on that.