Blackberry and 7digital officially unveiled their MP3 Music Store on Tuesday morning, complete with - you guessed it - 7 million tracks. All four majors, as well as a long list of independents, are part of the catalog selection.The rollout is happening across the UK, US, Canada, France, Italy, Germany...

The highlights: * Retail giant the HMV Group is investing £7.7M ($12.5M USD) in cash to acquire a 50% equity stake in 7digital * 7digital will power HMV music and video download stores in the UK and Canada and e-books store for Waterstone’s * HMV customers will have access to 7Digital's 6...