It's been reported that Ubisoft's upcoming sequel Assassin's Creed III will required a hefty install, and the title has already received its first patch.
The installation scales in at 4.5 gigabytes, and, after loading up ACIII for the first time, you'll have to wait for the required install to finish. Ubisoft might have implemented an install to cut back on the loading screens, but we won't know for certain until it launches tonight.
Incidentally, what usually accompanies a game launch is a game update, and that's exactly what you'll see when you boot up the game tonight. Luckily, the update is only 15 megabytes, but it'll probably make the install detailed above look longer. Let us know if you're planning on picking up Assassin's Creed III tonight; if you're already in line waiting for its release, let us know that too.