Innovation (gasp!) is a little bit overrated if you're talking strictly from a market impact POV.
Many of the most successful games, even the "new hit games" aren't necessarily the most innovative .... Just Dance and Call of Duty weren't neither was Uncharted or Mario Kart Wii or Gears of War.
But it isn't as bad as cynics think either, people do want freshness in their games, but it's the overall design of the game combined with where the audience is appetite wise at any given time that really determines things.