In addition, there's a new multiplayer trailer to gawk at.
I'm just interested to find out whether my PC can run the game at all!
If you haven't registered for the beta, you can do so here: http://neworder.wolfenstein.com/en-gb/doom
Physical copies came with a code. If you pre-ordered The New Order on Steam, it should just unlock for you when the time comes, but if you got it digitally somewhere else, you should have been emailed a code.
Yeah. This seems like a distant afterthought to me. Kind of nice we will get 4 days with it but... I don't know, if they advertised "Wolf: New Order with pre-order bonus of a 4 day Doom beta" maybe i've have thought... eh whatever. I'll take it.