Yes, you read that title correctly (I assume), Valve is teaming up with the TV network Adult Swim to work on something which is most probably related to Team Fortress 2. The Adult Swim web site has a promo page which states that the two companies “are teaming up for something that you’ll probably enjoy. To learn how their video game peanut butter will be getting in our network’s chocolate, come back next week.”
So further announcements await us in the coming week regarding this project. We can’t know what it entails for sure until then, but it will likely be additional TF2 content which is somehow related to properties owned by Adult Swim, either that, or it’s the other way around. It’s worth noting that footage of TF2 has been aired on Adult Swim programs before, so it wouldn’t be too surprising. Keep an eye out for updates on this if you’re interested.
Source: Adult Swim