In the case of the yen, the new Prime Minister Shinzo Abe has come into power with an aggressive easing agenda (both monetary and fiscal). The yen has been getting slaughtered since November.

In the case of the British pound (which has been getting hammered all year) the currency is weakening on a combination of weak economic prospects, a worsening balance of trade, and the expectation that newly incoming Bank of England chief Mark Carney will be inclined to ease policy further.

And George Soros is apparently going after both currencies.