I watched this musical in London Westend when I was there in mid April 2009. It was a really cool musical, the Billy Elliot was great. The energy for all the dance pieces by him and the rest of the supporting casts were really amazing. this is hard considering they have been repeatedly doing this for many many nights. Thus a real challenge for them to keep up the energy level which is vital in every performance. What the audiences see at the end of the nights on each performance has to come from this energy.
Of course a great musical must have all the great components and this story has some rather impressive component. here are the links to some productions videos on some scenes in Billy Elliot, and if you have a chance to visit the Westend, go catch it.