Apparently, Christine McVie will be returning to Fleetwood Mac to do more than play some old songs in concert. The group has just finished a two month run in the studio – the same place where they recorded 1979’s “Tusk” album. They’ve apparently been working on some new songs. “This has kind of been a project in slow motion, that’s the only way I can put it,” Buckingham tells Billboard. “We got in the studio not…