Finally, some proper simulated gaming facial hair is on the way in The Witcher 3 (didn't Kojima promise that in MGS 4 once?)
The info comes from a translated Gamestar.de article which, in a list of features, mentions, "Geralt's beard will grow over time".
Eurogamer asked CD Projekt's communications chief Michał Platkow-Gilewski about it and got this statement:
The beard grows as time passes and when Geralt moves between locations. The beard has several "states" and these states determine its length - the longest is really long but it's not Gandalf-long. When you download the free Beard and Hairstyle DLC the growth of the beard will stop because we decided that when players want a predefined look, it would be weird to require from them to reapply it time after time.
Hopefully, "long but not Galndalf-long" won't exclude a good viking style. Something about Geralt suggests he'd suit a strong beard, like some sort of medieval Jedi. That Beard and Hairstyle DLC mentioned will be one of 16 pieces of free DLC on the way.
[New The Witcher 3 information from Gamestar - NeoGAF]
[Geralt's beard grows as you play Witcher 3 - Eurogamer]