Well the series will have at least 5 season so I'm sure it's only tempoary like mind control.
**EDIT** I have a few reasons why it's most likly temporary Yeah I was thinking along the same thing. I have a feelinng it's temporary. For sevreal reasons. 1. The actress who plays Ahsoka is recoring Season 4 and says she feel's that Ahsoka is far away from the Darkside. 2. Anakin wouldn't have gone to the Darkside if his Padawan went because he'd pry kill her. 3. Previews are sometimes meant to throw 당신 off. 4. If 당신 look at her face in the pictue at the bottom her face is covered with something as if she has the Blue Shadow Virus again 또는 something of the sort. 또는 something like the Geinosain brain worms that haunted the Clones and Barris. And look how her eyes are yellow, I know this happened to Anakin in Episode III but that might be a not so good change. We don't know but I think it's temporary.
i seriously doubt that she will go to the dark side it looks like she is being controled 또는 possessed 또는 something it definitly is not permant i don't think. I mean 당신 can't have some one just out of nowhere go to the dark side and i don't think it will happen so don't worry its only temporary