From what I've seen they're basically 'making fun of' today's celebs (mostly music-wise). I've seen Katy Perry's California Gurls and Lady Gaga's Bad Romance. I also heard a rumor that they're also doing Jersey Shore.
Also, since we never talk about anything but our lives:
1. Do you like Someone Like You?
2. What do you think of the previews for the I Feel Like Dancing video?
3. What do you think of the previews for the Dirty Work songs?