The first reports from people with the codex in hand are filtering out on various websites. Here is the initial pass from german 40K site 40Kings:
This is translated from German, so you will encounter some odd turn os of phrase:
Gentlemen, this time there is really a premature birth. Rumor has it that quite a few people outside the HQs in Nottingham there that have the Codex Dark Eldar are on your desk. It's also said that this people want to present even a few interesting facts about the new Codex ... Below you will find a first estimate, based on rumors (!), Which are to me so came from here and there to ears.
Style of the Codex:
In principle, such as the new Grey Knights - no new units, loss of some known units for which there are no models, few new rules and basically a rehash of known with a few small changes here and there. Is that bad? No, not necessarily. DE Codex has always been moody and also the last issue had some charm. She was just not very strong game ... Is the new Codex game strong? I would say after the current rumors Location (!): Yes and no. A few gimmicks fall directly into the eye, but there is still no unity that could secure some form of stability or field presence. It remains questionable whether new gimmicks can make the really fat frying in the fire storm of colossi and Serpents ... But I've written anything yet!
Army-wide special rules:
Rumor had it already in the shady corners of the dark city. Power from Pain is a "vast army" become special rules, benefits from each model, that this special rule explicitly leads in profile - so all "normal" Dark Eldar units, Beast, Talos, etc. still do not. The special rule gives, depending on the running play special general rules on the quality FNP, Furious Charge, Rage, Fearless, etc. There may well be something out of it ... if not the support of these special rules would not necessarily be the most formidable representatives of the Codex. Some items or skills give bonuses to the number of moves, so that effects of turn 3, for example, already can enter turn 2.
The Warlord table is very unspectacular. Fear, Hatred here and there, a bit of skill in battle or even a Reroll ... yawn. The funny thing is the "Combat Drug" table to the benefit of all models with Combat Drugs (surprise ...). All effects are central and even throwing dice for all units. The implications are kept very strictly: each one specific profile value is improved by one point.
Changes in the selections:
Some units will be sorely missed in the new Codex, some other losses will be hardly noticed. This radical cuts are really already been made:
Vect is not in the Codex - it will certainly be a supplement released
The Baron is not in the Codex - he will certainly NOT be a supplement released
The poison-Duke is not in the Codex
Remain at known BCMs: Drazhar (fairly static), Lelith (as) and Urien (as well)
Otherwise, the selections are pretty much identical to the previous Codex
Changes in the units themselves:
The main change in the units over the last infusion is probably that the Beast Pack now more than 12 models (of whatever type) must include and the chimeras are simply too "demons" become so only a 5 + ward save can call their own. The flocks of birds have only 3 LP, the Clawed Fiend has for a rich profile for moderate point cost (but no protection mechanism). Funny is also that Tali and Croni (gnihihi) can be used in units of 1-3 and now have generic FNP. Not bad at all.
In addition, now all vehicles automatically "shock troops" are.
New equipment and weapons:
Again: Something New, but a few interesting ideas. The relics of the Dark Eldar are located in the middle of the power scale. A few inconveniences for enemy psyker, a couple of problems for opponents with low morale (unless they are Space Marines ... na thank you) and a few weapons and armor. Nothing exceptional. 35 For there is but the new Webway portal for the Succubus or the Haemonculus that the carrier and its unit (!) Gives shock troops and no deviation in Schocken. This can some games. I have quite a few nasty combinations with this tool occurred.
Also in the vehicle equipment, there are tried and true: Moral reroll, twin-linked Splinter weapons of passengers, etc. But also exciting things such as "Stealth" for vehicles. A 5 + ward save Venom continues to have on board.
New weapons are rare. Some special equipment à la Helfrost gun that is singular to have on a platform, has crept in, for example, a 5.5 storm 2 24 inch small template for the Talos. The rocket bomber (which is unfortunately completely overpriced) have changed something and otherwise we still saw the expected change in the Splinter Canon to a 4.6 weapon salvos. Here and there there are new melee weapons with irrelevant properties, also a few other minor modifications of existing equipment were made - the Shredder has now ... Warning ... shred! Good choice!
Based on the current situation rumors my first impression is bad, a lot of potential wasted. But: At least there's one or the other unit and combination, a small renaissance of the Dark Eldar will mean possibly that is set by the pure available goes from BCM. Unfortunately, the Codex is the currently chosen path away pretty consistently. Much is simplified and adapted a few general special rules is available as a spare. Thankfully, the old Codex quite interesting ... Now it's up to us to find the tournament players, the path in the network of a thousand gates, which will lead to a competitive Dark Eldar army. Quite simply, the be sure not to find. But excluded it is not safe.