The Rbrs didn't stand much chance anyway. If anything it'll help the Williams attack with less to worry about from behind. I don't believe anyone has the pace to get involved however. This is a straight fight between Hamilton and an incident or mechanical failure. I half expect Rosberg to hit Hamilton given the chance - he will know that the luck of a collision will be his best chance - and given Lewis is overly fond of aggressive moves I expect him to get that chance.
There's no real need for anyone else to bother them. I imagine Williams will have been quietly told to keep their noses out as they did to teams in 97.