Perhaps the most exciting feature of Street Fighter X Tekken is tag-team mode, which will allow players to fight as a team of two and switch between characters strategically. Characters include Ryu, Ken, Guile, Abel, and Chun-Li from Street Fighter, as well as Kazuya, Nina, King, Marduk, and Bob from Tekken.
You'll have to wait quite a while to get your hands on the game - Street Fighter X Tekken is due for release in 2012.