"We're thrilled to announce that Kenneth's long-time colleague and collaborator, Nicolas "Sparth" Bouvier will step into the position of Art Director," a Microsoft representative told IGN. "Kenneth will continue to work with 343 Industries remotely and partner with Nicolas in a newly created role as a Visual Design Consultant. We can't wait to share more details regarding the future of 'Halo' very soon."
It's unclear how much input Scott will have on the Halo universe going forward, though it seems likely that he'll have a hand in the design of the upcoming Xbox One Halo game. There's almost nothing known of that entry to date, beyond the trailer which debuted in June of 2013.
Nicolas Bouvier has long served as an artist for the Halo franchise, but his designs can also be found in Assassin's Creed, Prince of Persia: Warrior Within and id Software's RAGE. For more immediate examples of what Bouvier can do, pay a visit to his Tumblr where he shares many examples of his artwork.