So I guess most of us know that you can glitch out of the Beta Region. I won't say how its done since im not sure how the Mods treat posts about this so if you curious im sure there are posts about this.
What I noticed while exploring the non Beta Regions is that most of the Regions (espacially the ones that are not directly next to the Betaregion) are not finished, not even close to beeing finished actually. The Towns have no Buildings, there is nearly no Foliage, no Trees, the Streets are not textured, the Ground is not textured, there are holes in the World, there are nearly no Enemies, some of the Buildings that do exist are incomplete (sometimes you just see a Stair), and so on.
So if we take that into consideration and then take a look at the Releasedate its safe to assume that this Build is not the current one and infact atleast a few months old if not more. So close to release the World should be pretty much finished and what is left to do is polishing.