So far we've heard both Jemaine & Taika talk about writing a TV show together while promoting WWDITS and in an interview with the Guardian earlier this week, Jemaine mentioned that a four part, comedy has been commissioned by HBO:
HBO have commissioned a new, four-episode comedy show from Clement and Waititi, he reveals. “It was supposed to be this year but then we decided to put What We Do in the Shadows out ourselves.”
Also during a radio interview with Triple J, Jemaine confirmed that he is writing the TV show with Taika which isn't related to WWDITS (and is not Flight of the Conchords related, contrary to all the rumours that have been circulating).
Very intrigued to find out what it's about.