As I've said numerous times over, retailers get their release dates from the companies themselves. Stores, especially Gamestop who feed off reserves, like to start taking preorders as soon as their is confirmation of a release time. So when it came to Sadness or Duke Nukem Forever, both at one time had a confirmed publisher, but of course now that went away.
Try not to look at the release dates so seriously but it's not like they add them at random.








