I don't know if it was a stealth preview or not, and I have no idea what the purpose is, adult swim or not, but I just watched something called The Finkel Files. The artwork looked similar to Home Movies post-squigglevision, but otherwise I thought it was much better. I think it was meant for adult swim because there was quite a little scene about foreskin. Gotta love stealth previews!
It starred a young lad named Josh, who is going to Rabbi school, but he wants to be a musician. I don't know if the show itself is really funny, aside from the old rabbi guy, or if it's just highly amusing because that could have been Josh at age 13 or whatever :) Also, the whole bit about circumcision was hilarious.
Josh, if you can watch it next time it's on, let me know if you think it's funny. Old rabbis with lots of ailments crack me up. (Would you believe I was about to type Old Jewish rabbis. Like there are gentile rabbis.)