Ok...well only for a few nights...but it's still cool! Fleetwood Mac keyboardist Christine McVie came out of retirement last night, and joined her former bandmates on stage at London's O2 Arena! They performed their classic hit "Don't Stop." Check out the video below! McVie will also perform tomorrow night for the final London gig of Fleetwood Mac's current world tour. Also during the show, Stevie Nicks dedicated "Landslide" to Fleetwood Mac co-founder, legendary blues guitarist Peter Green, who was in the audience.