Confirmed: The Witcher 3 will have beards, horses and trees.
CDProjekt have also confirmed that this will be the last game set in The Witcher universe. The games are based on Andrzej Sapkowski's novels, though they are not considered canon (as Sapkowski rather brusquely confirmed a few weeks ago) for the future books in the world that Sapkowski is planning. CDProjekt are also working on an RPG based on the Cyberpunk pen-and-paper system, with their first game in the setting, Cyberpunk 2077, expected to be released in 2015.
The Witcher 3 will be released in 2014 on PC and (almost certainly) next-generation consoles.