German gaming website, Gamester have posted that The Witcher 3 will have different resolutions based on what platform you play on.
Here's a quote from the german site via Google Translate because my German language skills are pretty abysmal. Take the information below with a pinch of salt as the game still has 4 months in development.
In the duel console PlayStation 4, meanwhile, has clearly ahead of the graph. Although the textures are a bit more blurred than “high” PC details that falls within the normal TV-distance but hardly noticeable. In addition, the witcher adventure runs on the PS4 in 1080p – but only at 30 frames per second, which did not bother us.
On the Xbox One Geralt goes also with 30 fps on monster hunt, but only in 900p, the textures also seen slightly more washed out than on the PS4. However, polishes CD Projekt own words yet on the Xbox version, maybe you can still screw up to 1080p, but you would not promise anything. Stand now is the PS4 image the sharper and stronger colour.
From my time with the game at a recent preview event, I actually thought the Xbox One version looked the better of the two.
The Witcher 3 is out May 19th on Xbox One, Playstation 4 and PC