When it first started, people were told to either attend the Embassy on the appointment date or post off their application straight away. Then, reports said, the embassy started to do what they should of been doing and emailing people within 48 hours to say either the application was succesful and send the documents or they needed more information if for instance, the application wasn't completed to how they wanted it.
Perhaps somebody who has had a visa in the last couple of weeks can say what the state of play is now?
If not, then in the London online application folder, there is a post I made with the way and times to contact them.