Presumably because Fabio Capello is looking toward the World Cup campaign, he is "rotating" captains to help him decide who will be permanent captain, I doubt Beckham is in his long term plans.
Let him get the 100th cap out of the way, then whenever a squad is announced we wont have all the papers banging on about it. Once he as 100 caps, ifhe gets called up its on merit and not just so he can pass a personal milestone....