Turn 10 have announced that the Long Beach circuit is being made available for free download tomorrow and that it will be fully integrated in all appropriate game modes.
"The full eleven-turn, 1.97-mile course, home to this weekend's 40th running of the Toyota Grand Prix of Long Beach, is included, as well as two alternate ribbons: the slightly shorter East Loop and the half-mile West Loop, both of which are perfect for drifting or pushing your technical driving skills to their limits."
In addition to this a paid for "Long Beach Booster Pack", that's included in the Season Pass is also going up tomorrow. A trailer of the Long Beach circuit can be seen below along with pictures of the cars in the Long Beach Booster Pack.