There is a rumor that it will be available in the US in March. I don't know why it's taking so long. I read somewhere that the DVD was released in Australia (they're region 4) just recently.
If you have a blue ray player, the UK blue-ray is region free. If you don't and REALLY can't wait, you might want to check into all-region DVD players. A Google search will provide information. I've had one for several years now (when you're a fan of mostly British performers it becomes a necessity

)and it's great.