Despite reports yesterday of a leaked November 21, 2013 release...
Sony hasn't yet announced the release date for the PlayStation 4, instead opting for the vague "holiday 2013" launch window, but some leaked promotional materials seem to have prematurely revealed the exact date.
NeoGAF member Cyborg posted a photo of a sign for the PS4 at a Media Markt store in Amsterdam, Netherlands. It clearly shows the November 13, 2013 release date for the PS4 which, as others in the thread point out, fall in line with other European online retail outlets.
At this point it's unclear whether this is an official promotional item from Sony or if the store went ahead and made this without permission. Media Markt is a massive chain in Europe, similar to that of Best Buy here in America so while it's quite likely they already know the exact release date of the PS4, it's unknown if Sony gave them the word to put it up. I'm assuming they didn't, but I'm also betting this is not some made up ad.
For comparison sake, the PlayStation 3 was launched in the United States on November 17, 2006, so a November 13th release for the PS4 isn't too unreasonable to believe.