Is the mining boom over?

Companies such as Xstrata, BHP Billiton and Anglo American have been skyrocketing on the back of rising metals prices in recent years. But some metals, like copper and nickel, are now substantially off their highs. BHP and rival Rio Tinto are locked in a war of words over a potential merger, so arbitrageurs’ activity may distort their stock prices. But is
the sector going to remain a good play, or should I diversify out of it?