"We believe music genre sales for the company will be driven by an expansion of the release slate in 2009, which should broaden sales to core consumers," Creutz told Gamasutra. "We also believe that Guitar Hero is likely to face less competition from Rock Band this year, driving a gain in market share for Activision Blizzard."
Creutz does not see The Beatles: Rock Band as being a threat to Activision.
This is mainly due to the high price point of the collector's edition. Creutz said it will do nothing to help out peripheral sales.
He does, however, believe that Acti's DJ Hero will freshen up the genre and cause a surge in peripheral uptake.
More through the link.