I think their idea of basing it on humour is stupid, Big Brother is at it's funniest when it doesn't intend to be, with housemates like Jade, Nadia and Marco providing the laughter. Endemol need to keep in mind that everybody has a different sense of humour too and they can't appeal to everybody's at the same time - which means they are certain to alienate viewers. I don't want the humour to be forced onto us, just let the housemates provide us with the entertainment.
/rant
I'd rather they just continued with the evil theme to be honest, and ensure they have a wide variety of characters - last year's series was fantastic and it would be a shame if BB6 didn't continue with the momentum.