BBC News: Brass in pocket.
The backs of the one, two, five, 10, 20, and 50 pence pieces and the pound coins have been redesigned. The main change in the design of competition winner Matthew Dent is that the coins all feature different parts of a single image, the Royal Shield of the UK. The size, shape, material and weight of the coins remains the same, but there are subtle and significant differences in the designs. The reverse design of the Â£2 coin is completely unaffected.
The article has a picture of the new coins, and I think they look rather odd. I remember the 20p coin being introduced and I love the Tudor rose design on the back of it. I also remember the demise of the half penny coin, and the shrinkage that afflicted the 5p, 10p, and even the 50p coin. Wikipedia has a more comprehensive article on the new coins.
Update 12th April
Clive James weighs in on the new coins.