It was pseudo-confirmed before and now we have the official press release.

Namco Bandai has confirmed that Soul Calibur V will launch on January 31 in North America and February 3 in Europe for the PlayStation 3 and Xbox 360. The publisher also confirmed that Assassin's Creed protagonist Ezio Auditore will be the special guest character.

Ezio will be able to use a Roman Longsword, Stiletto, Crossbow, Hidden Gun, and his trademark Hidden Blade in combat. Also, for Europe, Dampierre from SoulCalibur: Broken Destiny will be available as an exclusive pre-order bonus playable character; not sure if this deal will be in effect for the US.