The Sword of Destiny, 'The Tower of the Swallow (published as The Swallow's Tower), and The Lady of the Lake will be officially translated.
The Sword of Destiny will be published May 2015, alongsider The Witcher 3: The Wild Hunt
The Swallow's Tower and The Lady of the Lake will be published sometime in 2016, and 2017 respectively.
The Books will be translated by David French who translated the first two novels of the saga.
http://www.gollancz.co.uk/2015/01/gollancz-acquire-three-more-witcher-novels/