Update (9/1/2015 at 2:45 pm): On his Tumblr, "She-Hulk" cover artist Kevin Wada clarified his role in James Robinson and Vanesa Del Ray's upcoming "Scarlet Witch" series:
I wanted to address this as people have been hitting me up inquiring. When I did the redesign for ['Scarlet Witch'], I was told I would also be doing a promo image of her, which was used in the solicits for the All New All Different Marvel campaign -- and that's all. When I saw it was marked down as 'cover art' I was very surprised and I had been given no indication beforehand that my promotional art would be used as any cover ever. I had/have no expectation that I would be doing covers for the book as I know that Marvel is taking a different approach with this series in terms of artists and it sounds like it could be really exciting for you readers. I would have clarified this all earlier but I knew Marvel would announce their plans in due time. At this point I don't know if my promo image will be used to launch the book any further than it's already been used, and that's okay because seriously look at this beautiful cover. David [Aja] is a beast and this cover is bootiful and, honestly, I'm just so excited to be seeing him draw my redesign over and over. And Vanessa [Del Rey] too. I'm just giddy. To be seeing the design we came up with realized by all these amazing artists is mind blowing.
Earlier (8/31/2015 at 1:15pm): A few months after being initially announced, "Scarlet Witch" #1 now has an interior artist attached. As reported by Newsarama, Marvel has announced that Vanesa Del Rey will be the artist for the debut issue of the new "Scarlet Witch" ongoing. Del Rey's work was most recently seen in the pages of "Constantine: The Hellblazer" for DC and in BOOM! Studios' "Hit" prior to that.
"Scarlet Witch" will be made up of a series of standalone issues, with a new artist tackling each chapter. The series, which will be written by James Robinson, will explore the world of Marvel's witchcraft and focus on Wanda Maximoff and her quest to save other witches.
"She wants to fix it, because it's important to her as a witch," said Robinson in an interview on Marvel.com. "But [she] also [needs to] discover how it was broken, and if someone broke it, who that was. Also, she suffered from periods of mental instability, and she wants to know if that's something that she needs to treat herself with the established ways that you treat mental illness, or if the practice of witchcraft is affecting her mentally as well. She has a personal stake, as well as a sense of wanting to fix it in the big picture."
The announcement of Del Rey for "Scarlet Witch" #1 was paired with the reveal of "Hawkeye" artist David Aja's cover for the debut issue. Aja is listed as providing covers for the series. "She-Hulk" cover artist Kevin Wada was originally solicited as the cover artist for the series; his art can be seen in the series' teaser.
"Scarlet Witch" #1 arrives in December.