I've spent a day with the new Dark Eldar Codex so I thought I'd give my initial thoughts. First up, I like it. As with all of the 5th edition books, the fluff section is brilliant really giving you flavour of the army. Onto the army lists, every FOC slot has really viable choices. In fact I'd go as far to say that every unit in the 'dex has its uses. There's no Pyrovore here. Obviously, it's one thing looking good on paper it's another thing working well on the table. I think that the hardest section to choose will be Elites as there are a lot of very good looking units in there.
As always the named characters are pricey but they all bring something important to your army. A quick mention must go to Lelith here as she gets 10 Power Weapon attacks at WS9 I9 against a Space Marine Tactical squad. Ouch. The standard HQ choices (Archon, Succubus & Haemonculus) all start cheap but can soon rack up the points with all sorts of esoteric wargear. Yesterday, Jes said that the design team had been given a clean slate when it came to designing the DE and here is where you can really see it. You can actually see the influence of Warhammer here as there is quite a lot of one shot weapons with a lot of rules. In fact this is possibly the one area of the book I don't like as it feels like there are slightly too many choices and it would be very easy (for me, at least) to forget about some piece of wargear in the heat of battle.
This is definitely a book where you really have to plan out your army as the interaction between units can drastically alter how the army plays. My first instinct was to go, "Ooh, that looks cool, I'll take one of those. And one of those. Ooh, and that" rather than actually thinking about how it would play. If nothing else I think that playing DE will help my list-building skills and my overall play on the tabletop since you can't just rush them forward and rely on a 3+ save like you can with Marines. I'm not going to do a full Codex review as I'm sure that Stelek and Kirby will do a better job. However, I'll keep posting as I build up my army and start using it on the tabletop.