Of all of the DCU movies headed our way, the one we know the least about is Green Lantern Corps. And maybe that's because it's so far away, not expected to hit theaters until 2020, or maybe because Warner Bros. is still gunshy after the way the last GL film went. But we may seeing the veil lifted sooner than we thought, because The Wrap says a member of GL Corps will be appearing in next year's Justice League movie.
They don't actually say much, which may be why the news was an afterthought in a much larger piece. The only say “a member of the Green Lantern Corps will be seen in Justice League in a key sequence.” That implies this won't be Hal Jordan or John Stewart, the two GLs most are familiar with. But likely it'll be one of the various alien races who hold power rings. Kilowog, maybe? That would be cool.
At this point there is still no director, no writer, and certainly no stars, but if the Corps hits the screen next year, even in a cameo, it means Warner Bros. is feeling pretty confident. Justice League opens November 10th 2017.