When I re-downloaded the software this morning I am see Simplify3D-4.0.0 installed, though my installed version is 3.1.1 and when I check for updates it says it is up to date. After installing 4.0.0 it has a new folder directory and did not update 3.1.1, also the website change-log does not indicate a 4.0 release.
Just checking if it's just me or it is released, if so I am pretty happy considering I just purchased the software and a major release comes out