According to a tweet by the official SoulCalibur Twitter account, 2B is set to release in-game on Tuesday, December 18.
Release date: no longer confidential.
Stand ready for battle: @NieRGames 2B will bring her blades to the stage of history on December 18th in #SOULCALIBUR VI!"
Her inclusion in the fantasy fighting game was revealed last October as a DLC fighter. Assuming the same price as Tira, a SoulCalibur veteran character, we can expect her to cost about $6. She is also available as part of their $30 DLC season pass.
As much as I love Geralt, 2B is my favorite guest fighter this time around.