This document functions like a sort of written trailer for the upcoming Wrath & Glory. An advertisement that explains the premise of the game, it is unfortunately devoid of any preview of the actual rules, but does a good job describing what you can expect in future products in regards to setting, plots and potential characters. For more detailed information about the system, one is definitely advised to follow the advice about visiting the linked website, as it feature some interesting crunch that is not even hinted at here.
Personally, I am rather excited about finally seeing a unified 40k RPG system which, rather than the previous scattered product line by Fantasy Flight and its laser focus on specific themes (resulting in mutually incompatible rulesets), gives players the ability to bring (nearly) all sorts of characters into a single story, thus presenting an opportunity to play with "mixed parties" the likes they might know from and even expect of the franchise due to how the setting was originally described in the tabletop material and its stories/history or some of the fiction. Furthermore, this unified approach should also make it much easier for the creator to expand the game with new material that is of use to everyone.
A Commissar fighting alongside Space Marines like Yarrick on Armageddon? A Guardsman holding their ground against Chaos Marines, just like Colonel Straken on Catachan? An Eldar and a Battle Sister striking a wary alliance to fight a common foe, like in Daemonifuge? Wrath & Glory aims to make all of this possible, and more. If the rules hold up to what the designers are promising, this game should be of supreme interest to any 40k fan.