He is wanted for extradition on a criminal warrant to another European country for sex crimes. I am not going to argue about the validity of the charges; they have been well documented in the press. You can either believe the female accusers or Assange.
I think that would make great bad publicity for England. Point an Lrad at the embassy huh. Assange is smart he did this intentionally. Big bad bully beats up on whistle blower.
Worked to get Noriega out of the Vatican embassy in Dec 1989 and in many other instances. Besides.... England can just claim they are replaying the closing ceremony of the Olympics.