The Cauldron of Blood, and Bloodwrack Shrine variant, are probably the most welcome updates. Not only was the old cauldron stuck in the 80's, it had very little conversion potential. Looking at these shots I'm bubbling with ideas (mostly revolving using the Khaine statue) Wouldn't that make a great c'tan, or Eldar Avatar? The serpentine medusa also holds some interest for me, namely her potential use in a Daemon army as a Keeper of Secrets or Herald.
The next most interesting addition is the Kharibdyss model. In case you don't know the reference, Charybdis and Scylla were a pair of immortal monsters that Odysseus had to sail between in the Odyssey. Charybdis was a monster that created giant whirlpool that would swallow ships whole, which plays nicely with the Dark Elves niche as seafaring pirates, and monster wranglers. Maybe they'll make a Scylla monster at some point.
No Dark Elf army would be complete without an assassin. Shadowblade here looks neat, although that cape begs for some details to be painted on it so it doesn't look like a trash bag flapping behind him.
Rounding out the rest are some new units. The Witch Elves look like they're banking on the popularity of the plastic DE Sorceress mini. The Sisters of Slaughter appear to be from the same box, and I'm guessing they represent warriors from the Cult of Khaine. I think I prefer the Witches. Then you have the Dreadspears. I guess the DE needed their own equivalent to the HE Sea Guard. Eh, they don't appear to be fancy, but they'll probably have an important role in the army book.
More when I find it.
~Muninn