http://news.bbc.co.uk/sport1/hi/boxing/7172156.stm

From the page: “Joe Calzaghe’s super-fight with Bernard Hopkins will take place in Las Vegas on 19 April, it has been confirmed.

The non-title bout will see undisputed super-middleweight champion Calzaghe, 35, step up to light-heavyweight and fight in America for the first time.”