Looks photo shopped to me. Of course if blizzard put that in there, they would probably use photo shop too. I don't think there are any post beta renders of that though, and the pre-beta ones never had that text in them.
Did some research, and found a link to the image from 2008.
EDIT: Actually I remember them saying once that they put a tun of detail in the cinematic. Think the quote was something like "from the hairs on his face to the numbers on that screen". Maybe these dates were their planned "summer release" dates, and when they were originally expecting a summer release they put them in, and they just re-used the same dates (why would they change?) after the delays. Or it could be a crazy coincidence.
I think that Legacy of the Void will be released in 2-3 years like before. If you read the reddit post, they said they finished writing the story. I think that it will be announced in blizzcon 2014. Beta will be released late 2015 and LotV will be released early 2016.