HBO Moments Spring 2011, the new shots are later in the vid.
Frame by frame breakdown in HD by the wonderful people at Skarsgardfans.com
I think their speculations are spot on. Here's one but they have several at the link above. Poor Eric, he is witch-smacked, he never looked so blanked out.
First Fan Question Answered …
By Gianna Sobol
Will the witches wear pointy hats, have crooked noses and have warts or will they look just like me and you... the average but beautiful Jo?
I talked to Ben Hayes, the writers’ assistant, about this one, because he was in the room when the writers were deciding how to characterize the witches. He said that it was inspired by the characters in the fourth book by Charlaine Harris, but that in bringing Marnie to life, they were trying to create a character that seems real, but slightly "off." The witches in Season 4 all follow that approach and are a range of personalities and looks.
Ben also shared that "as far as the magic goes, there was a good deal of discussion in how to depict it in a visual medium. The writers wanted the magic to suit the stories and nature of the show, but also to meet the needs and opportunities of production. Several different traditions were researched and discussed in order to come up with a unique take on witches, witchcraft and magic in the world of ‘True Blood.’"
HBO's Inside True Blood Blog
Pointed hats and warts? OK, I guess the questioner thought that was good to ask, I hope it was tongue in cheek.