Here’s the game-changer: BSkyB is thinking about broadcasting the April 29th Royal Wedding in 3D. TV experts wonder if Prince Williams’ wedding to commoner Kate Middleton might be the technology boost that the Queen’s 1953 Coronation was when many England’ers bought their first TV sets to watch that royal spectacle. And it may be that people worldwide do the same thing for this wedding and 3D. Sales of 3D TV sets in the U.S. have been modest so far. (Screen Digest predicts there will be only 4.7 million 3D TV sets installed in the U.S. by the end of 2011.) If Sky does go ahead with 3D then it will feed those signals to its international news affiliates. But BBC Vision boss Jana Bennett sounds pretty unenthused about the prospect of the BBC filming in 3D though — “although I can see an archive argument,” she tells me.

The Beeb will definitely be filming next April’s wedding in high-definition. TV technology consultant Chris Forrester thinks that broadcasters will use the Royal Wedding to promote HD to those who haven’t yet upgraded to HDTV sets/receivers.

UK broadcasters will be hoping for record viewing figures in what could be the most watched TV event in history. A total of 28.4 million British viewers tuned in to watch Prince Charles marry Lady Diana Spencer in 1981. Over 750 million tuned in worldwide to see that wedding dress trail up the steps of St Paul’s Cathedral. Media outlets including the BBC and BSkyB already have met with Buckingham Palace officials at Clarence House, the Prince of Wales’s official residence, to discuss broadcasting arrangements for next April’s Royal Wedding. My source says nothing was decided and the meeting was just a meet-and-greet.

The big news about who is going to be the lead broadcaster will be announced in the New Year. However, the likelihood is that the BBC will have that job providing pool footage for every broadcaster around the world to use. (“Otherwise,” the BBC’s Bennett tells me, “too many people will be falling over each other’s camera cables.”) U.S. broadcasters will have access to these live pool feeds. But who will oversee the pool footage? And will U.S. broadcasters be charged for it? My guess is that it may be handled the same as Prince William and Kate’s engagement interview. ITN, the news arm of ITV, filmed it and sold it internationally with revenue going to a charity of the young couple’s choice.