On the Campaign front, enemy aggressiveness has been decreased for Veteran Difficulty to better the single-player experience, and player health has been reduced to compensate. Bots have had a bunch of restrictions lifted, which should allow them "to be more helpful and effective, while still not beating the game for the player." They should execute more vulnerable enemies, for example, rather than leaving so many for you to finish, and will focus fire on those pesky psychic Zoanthropes.
Private Mode has been added for Operations, which means you won't have to suffer through automatic matchmaking when trying to play with friends (or solo). Intriguingly, a bunch of tweaks to the AI Director and spawn rules will mean the maximum number of those frustrating Tzaangors with shields allowed on the battlefield has been reduced from ten to four; similarly, Cultist Snipers are restricted, down from ten to three. Changes to perfect parry means you will get some armor back for dispatching Minoris-level foes.
In PvP, the player spawn system has been improved and should result in fewer one-sided massacres. The Vanguard's Grapnel Launcher has also been reworked in this game mode. Instead of a full stun, it's a stagger that inflicts a significant slowdown effect.
Will you be diving into some Space Marine 2 this weekend? Are there any particular changes you are still hoping to see? Duel with chainswords in the comments section below.