The Royal Navy has killed three pirates in a brief firefight after responding to an attack on a Danish cargo ship off the coast of Yemen. International sea law will hopefully still allow them to kill the other pirates on the dhow after a proper trial.
We'll see if the US Navy gets into the act anytime soon. The Navy has largely been sitting out the War on Terror (except for supporting the Marines) and anti-piracy efforts would be a great way for the service to become more relevant. Perhaps some of the littoral combat ships could be put to good use. A cheaper (and probably more effective) alternative would be to field some q-ships for anti-piracy operations in hotspots like the Gulf of Aden or the Strait of Malacca. Or maybe just smaller littoral vessels like Sea Fighter.