It is possible that this is not something new, but this was my personal first experience with it.
I just watched The Daily Show and The Colbert Report on Hulu and, for both shows, I was given the option to play just one 2min+ commercial at the beginning then watch the full episode with no further commercials.
I played the long opening ad, opened up another tab and caught up on some Facebooking, then watched the show ad-free.
It was awesome.