Here is a list of the nerfs announced by Feast of Blades for their 2014 40k GT. I have chosen to focus only on the nerfs to the core rules, codices and supplements since Escalation and Stronghold simply repackage the new Apocalypse book with a few new rules thrown in for some semblance of good measure. My gamer instinct tells me neither will make it to the competitive environment at most of the major events so I want to cover the nerfs that will have the biggest impact on anyone who decides to attend.
1) The Grimoire of True Names from Codex: Daemons is banned
This is one of the many big nerfs to Chaos Daemons... Seems like they got picked on a lot (see more nerfs below). The Grimoire is already self balanced as it only enhances the daemons' invulnerable save 66.667 percent of the time (not including the re roll for Fateweaver's Staff of Tomorrow)... The other 33.333 percent of the time they have a worse invulnerable save.
2) A few units will receive 0-1 status
We all know this list will include the Heldrake... Chaos Space Marines are definitely overpowered. What was GW thinking ??
3) Supplemental Codices will no longer be able to ally to their base codex
Nerf to the following armies so far (will nerf future release):
—Chaos Space Marines (like they really need to be toned down)
—Eldar
—Tau
What about an army like Space Marines that can ally with itself via their codex? Tyranids are also rumored to be able to ally with themselves with the new release. Will these armies be allowed to loophole this nerf?
4) Dataslates will take an ally slot
So you can just take Be'lakor as an allied detachment... Interesting but doesn't make seem to make much sense in this regard.
5) The number of psychic mastery levels in an army will be limited
Not much detail - will probably be a nerf to the following armies:
—Chaos Daemon FMC Flying Circus
—Jetseer Council
—ScreamerStar
This could throw a monkey wrench into the upcoming new Tyranid codex... Heck it's not even out yet. What's up with that?
8) Dedicated transport flyers will be limited
Big nerf to Necrons! Who else has dedicated flyers with transport capacity? This could easily be addressed with the mission rules - come up with something original to stop the last turn objectives grab... Shouldn't be all that hard to do.
Nobody likes ScreamerStar much (apparently not even those who play the army) so let's ruin it for Chaos in general; i.e., Chaos gets the proverbial shaft. Interestingly enough top tier armies such as Taudar are relatively unaffected. Do you really think Riptides will be relegated to only one unit?
Why weren't the following included in the list of nerfs:
—Ignore Cover (Tau on a 2+ and eldar I'm looking at you)
—SerpentSpam (you don't really believe they'll stick to the Wave Serpent but it's okay for the Night Scythe... Right)
—Two or more Rune Priests with Jaws of the World Wolf all hopping out of a drop pod the first turn... Plus they are one of the two remaining things that reliably shut down enemy psychic powers - how is that fair - isn't that what this is all about ??
—Psykotropic and Rad grenades (these both are an uber boost to IG blobs using the new Inquisition supplement)
—The Black Mace coupled with the Enfeeble psychic power from the Biomancy lore... If you're going to screw Chaos then make sure you nerf everything good they've got
The question should be asked - Looking over this list, which armies can take advantage of these nerfs and still be abused... Why? Because you are going to see a lot of those; i.e., all that happens is the meta is shifted—rinse, cycle and repeat. Worst of all some of the existing top tier armies are not really suffering much at all as I've already pointed out.
Think about it... Maybe your army will be next on the chopping block. Good luck with that !