UPDATE 22/07/0215 10.30pm: This upgrade offer will also be valid on Xbox One, a Bethesda rep confirmed to Eurogamer.
As far as physical copies go, the rep told us "retailers will have trade in incentives as well. Folks should check with their preferred retailers on what those deals are."
ORIGINAL STORY 22/07/0215 5.06pm: Dishonored: Definitive Edition's PS4 version is half off its usual $40 / £30 asking price if you own the original game on PSN.
As spotted by eagle-eyed Redditers, this offer shows up on the North American PlayStation Store where you can pre-order Dishonored's Definitive Edition now. It will likely come to the EU PlayStation Store too after today's PSN update.
The original Dishonored was a free download for PlayStation Plus subscribers earlier this year, so anyone who accepted that offer will be able to snag its remaster for half price.
Since Dishonored: Definitive Edition isn't on the Xbox marketplace yet we can't confirm that this offer extends to Microsoft platforms, but it seems very likely that it will. We've asked Bethesda for confirmation on that.
Dishonored: Definitive Edition will include shinier graphics and all its DLC. It's due on PS4 and Xbox One on 28th August in Europe and 25th August in North America.