During Activision's Analyst Day conference CEO Mike Griffith confirmed what most of us already knew, while Treyarch is currently finishing up Call of Duty World at War, Infinity Ward is already developing the next installment in the Call of Duty series, which is expected next year. Griffith also revealed that Activision Blizzard plans to triple the amount of Guitar Hero retail titles and downloadable content by 2010, which was already hinted at with the FreeStyleGames acquisition last week. The music royalty debate got a little bit more interesting as Universal Music Group CEO Zach Horowitz stated that it has seen on average a 200-300% retail sales boost of material which is included in the Guitar Hero titles.