7digital brought its 13 million track-strong music store to the BlackBerry Playbook earlier this year, and it looks like it now has another new platform in its sights. The company confirmed today that it plans to release a music store app for Windows Phone 7.5 devices in January, apparently with a little help from a partnership with Microsoft. In addition to that rather large music library, 7digital's store is also notable for offering many of its tracks in 24-bit FLAC format, with the standard offering being 320kbps MP3 files -- 7digital also claims to now have 3 million customers. Whats' more, the company also announced toda