Finally saw it this afternoon. I was prepared to be sceptical, after all the hype but it's a very fine experience with brilliant acting by Colin Firth as King George VI, Helena Bonham Carter as Queen Elizabeth and Geoffrey Rush as Lionel Logue (the Australian speech therapist).
It turns out that King George VI died of a coronary thrombosis, brought on by heavy smoking, in 1952 after only 15 years on the throne.