Just ran across this; it's Gary Moore (http://www.youtube.com/watch?v=XXYjEMTQRm0&feature=player_embedded#) walking out on to the stage at Wembley at ripping through Red House.
I saw this concert on VH1 Classic recently. Gary Moore is nothing short of awesome here. The show has a list of big name guitarists all playing Strats for the Stratocastor 50th anniversary. Except for Brian May. He sticks with his usual instrument.