You can already download the trial version of the release version if you login with your adobe account:
Mac
trials2.stage.adobe.com/AdobeProducts/PHSP/13/osx10/Photoshop_13_LS1.dmg
PC
trials2.stage.adobe.com/AdobeProducts/PHSP/13/win32/Photoshop_13_LS1.7z
... but no Nikon D800 Raw support actually...
Mac
trials2.stage.adobe.com/AdobeProducts/PHSP/13/osx10/Photoshop_13_LS1.dmg
PC
trials2.stage.adobe.com/AdobeProducts/PHSP/13/win32/Photoshop_13_LS1.7z
... but no Nikon D800 Raw support actually...