Now that life is getting back to normal, I've picked up the new 40K rules and had a chance to read them cover to cover. The biggest difference from previous editions is that it's been split into three different books, one each covering models, background, and rules. This is pretty awesome, as it makes it much easier to carry the rules to games without having to carry around 300 pages of extraneous material.
Book 1: A Galaxy at War
This is the model section of the new edition, and is exceedingly well done. I can see why they start with the models, as it is the first reason most people start playing the game. The book starts out with several example armies, describing the units involved and their history. It's a good example of how GW wants armies to be built, as an organic whole that reflects the fluff. This is followed by almost pornographic spreads of the models from each each army. These are absolutely beautifully done, with the photos displaying the models as full size or even larger. I can absolutely see picking up this book as a reference or just a source of inspiration for a long time.
Book 2: Dark Millenium
The background hasn't changed or advanced, so this is business as usual. However, I do think it's more consistent than usual. They've incorporated some of the information from the Horus Heresy novels to flesh out how the Imperium functions, so it makes more sense than before. However, they keep the discussion on the 41st millenium, only discussing the Heresy as it explains current events. In addition, I think they took a page from Forgeworld and included some detailed accounts of military campaigns. These are more about the forces involved and the military events than the space operas about named characters that were in previous editions.
Book 3: The Rules
This unimaginatively named tome includes the rules to play the game, and it's what most experienced players want to know about. I won't go into specific rules yet, but I will echo the common sentiment that it seems like a very cleaned up 6th Editions. Many of the old unclear rules have been tightened up, and the whole rule set generally makes a bunch of sense. When USRs are referenced by the main rules (such as units being Fearless when embarked on Transports or Bikes being able to Jink), the USR is included on that page as well as in the appendix. This makes it a bit repetitive to read, but it will make it a much better reference.
That said, the only really new features are the new psychic phase and the Maelstrom of War missions. Beyond that, 7th Edition will feel very familiar to anyone that played 6th Edition. I'm not too bothered by this, as it means it won't really mess with my Space Marine Review. I'll only have to re-do the Librarian.
I think that's enough for this post, so I'll save my thoughts on some of the more important changes for my next post.