I'm not so sure-- VIZ needs editors for all of its licensed materials, too, after all, and the job listing doesn't specify anything about original content; it even says that the editor's job involves suggesting new acquisitions, presumably from Japan as well as possibly original.
But there is another piece to the puzzle: a new post today from Rob L. McCarthy, creator of the webcomic Hell On Wheels (along with Sheanon Garrity) and a VIZ editor, on VIZ's blog. In his post he offers advice to new manga and comics creators who are submitting their work, and it sounds like it comes from his own readings of such submissions-- which seems to imply that VIZ is still looking over new works.
So, sounds to me like there's still something going on, at least.
