Unreal Engine 4.12 was officially released today even though UT has been using a pre-release version of 4.12 for quite a while. One of the big new features is the new Sequencer for real-time cinematics and cutscenes. If you’re using Matinee to make fly-throughs of your maps, you might want to take a look at the new features in Sequencer.
As usual, the full changelog is freakishly long. Go HERE for the full details.