Thursday 3 January, 9pm: Put the date in your diary (or mobile phone calendar thingy), and be in front of your telly. Yes Channel 4 has announced the start date of Big Brother: Celebrity Hijack. And rather cunningly, they're showing the live launch programme on Channel 4, even though the rest of the month-long series will be live each day on digital sister channel E4 only. As we previously revealed, Dermot is hosting (which means he'll have a little holiday of a couple of weeks between the end of X Factor and the start of BB: CH, as we'll have to get used to calling it), and different celebs will become Big Brother and get their chance to tell the housemates what to do. Oh, and the housemates are supposed to be specfic talents in their fields. This is exactly what Channel 4/E4 is saying about the show:

"Dermot O'Leary hosts this live launch show as E4 hijacks Big Brother from Channel 4 and takes over the Channel 4 airwaves for an hour. In this one-off special simulcast to herald the start of E4's Big Brother: Celebrity Hijack series, viewers will see for the first-time celebrities taking on the role of Big Brother as they oversee a talented group of young housemates. Live from the Big Brother compound, Dermot will introduce each of the housemates as they enter the famous house that will be their home for the next month. And these are no ordinary housemates – they have been handpicked by Big Brother for being extremely talented in their respective fields whether it's music, politics or sports. This is a series with a difference, as in an unprecedented move, Big Brother is allowing a host of celebrities to take a turn in the hot seat and try their hand at the Big Brother role. The celebrities will be putting their own cheeky spin on the proceedings as they set tasks, give instructions in the Diary Room and generally cause havoc. But just who will be the first celebrity to hijack the role of Big Brother? Find out in January and see just how the housemates will react to their new master and to each other, when they enter their new home. The series continues on E4 following the launch show on C4."