So, to end the speculations: Time needed for testing is time which is needed. The time is used to play through the game several times. Also this time includes additional fixing if changes brought into the game resulted in bugs. The testing time however should end this evening and if the testers can't find a major bug or a showstopper, steam will be ordered to release the patch for everybody.
I can, right now, confirm that there were again some changes. full changelog will come along with the patch.