The Serpentine Gallery has stolen a march on the Saatchi show with their blockbuster there, a massive undertaking with 200 works by 50 artists. The curators were Hans Ulrich Obrist and two others. Matt McCormick's 'The Subconscious Art of Graffiti Removal' has removals men carrying out a pastiche of Newman and then Rothko, whitewashing all the way. Mika Rottenberg investigates obesity, not without a cynical side-sweep. Is this show bordering on the endgame, as US critics viewing the show before transhipment indicated. Is the hidden agenda that US Art is brazenly political here? If so, in London it appears falsely provocative.