It’s been a badly kept secret, but the games-playing world now has the first official confirmation that there will be a DJ-based spinoff from the Guitar Hero franchise. The game’s site has just launched, though it doesn’t tell us anything other than that it will be available for X-Box, Playstation and Wii.

The game will be competing with Scratch: The Ultimate DJ by 7 Studios (pictured below). That game has more details publicly available: there’ll be a controller based on a turntable and, while the heart of the game will be similar to the concept of Guitar Hero and the like, there will be more room for improvisation.

The rival games will also be doing battle to get the involvement of celebrity DJs.  Both DJ Shadow and DJ Z-Trip are expected to be involved in DJ Hero, but Mixmaster Mike is already signed up to Scratch.

DJ Hero will be one of the first tasks facing Dan Rosenweig, a former Yahoo executive who has taken on the role as president of RedOctane. That’s the Activision division responsible for the Guitar Hero series.

Rosenweig’s jump was only confirmed yesterday, but he’s already spoken about his work. He told The Hollywood Reporter that as far as the franchise goes, “the present is awesome, but the future is significantly bigger.” He noted that DJ Hero will be coming out “at the end of the year”, which presumably means it will be aimed at the Christmas gift market.

DJ Hero comes as Activision recovers from news of a $72 million loss in the last three months of 2008, despite the company producing four of the ten best selling video games. Analysts believe the hugely successful music-game genre may have reached its peak and firms could struggle to find new ways to make money from fans. Figures for both January and February show sales of music games across the industry down by around a third, despite an overall rise in game sales.