Earlier today, the official Deus Ex twitter account tweeted what I suppose you'd call a release date teaser, i.e. the above image but with the important numbers covered up by two Eyes of Providence, with the caption "Today is going to be an interesting day." An hour later they tweeted the unobscured image with the date in that backwards format they use in the States, so I'm afraid "interesting" may have been pushing it.
In fact, the most interesting thing that I can see is that Sony presumably had some kind of deal that let them reveal the release date—naturally only mentioning the PS4 version of the game—half an hour earlier than the Deus Ex account itself. But not to worry, we waited to make sure the PC version would arrive on the same day and apparently it will, on Steam, on February 23 next year.
Not sure if you'll want it yet? Check out some gameplay or watch the devs have some fun with a Let's Play.