Watch Dogs 2's first DLC, the T-Bone Content Bundle, is out right now on PS4, and it will release for Xbox One and PC on January 4.
In this bundle, players get access to T-Bone's signature clothing and a (very heavily) modified school bus (more of a bulldozer, really) named Bertha. Seriously, that thing is a piece of work. A new mayhem co-op challenge is coming as well, accompanied by a new enemy type called the Grenadier.
Unfortunately, it doesn't include any new missions; it's a fairly small DLC bundle aimed at delivering extra content to experienced players. However, it is the first in a line of planned DLC such as No Compromise and Human Conditions, which will include new missions, story content, and co-op modes. Keep an eye out for those in the spring.
If you have the Watch Dogs 2 Season Pass, you're all set; the T-Bone Content Bundle is included. If you don't, never fear, because you can purchase it by itself - and if you feel like treating yourself, you can snag the season pass for $19.99.