Namco Bandai Games will be releasing a free-to-download DLC pack for Tekken Tag Tournament 2 on October 9, 2012, a Famitsu report confirms (via Joystiq). The downloadable content amounts to six new characters -- Dr. Boscnonovitch, Slim Bob, Violet, Miharu Hirano, Sebastian, and Unknown -- and four new stages, set in Russia, Chile, Saudi Arabia, and (awesomely) "Magic Show."
It sounds like the content won't be released as a single pack, but rather as a series of smaller, bite-sized DLC drops. The important thing to remember is that it's all FREE. It's also worth noting that the six new characters are the same bunch that were discovered embedded in the game's code by tech-savvy fans shortly after its September 11, 2012 release.