I'm not sure how NECH is leaking from Germany on September 19 when the set officially comes out on November 7, but hey. I'll update this post more as I get more details!
The first thing I've seen so far is Virgil:
"1 Tuner monster + 1 or more non-Tuner monsters.
You can only control one "Virgil, Rockstar of the Burning Abyss". Once
per turn, you can discard one "Burning Abyss" [card] to target one card
your opponent controls or in their graveyard; shuffle it into the deck.
If this card is destroyed by battle or card effect and sent to the
graveyard: you can draw 1 card. You can only use this effect of "Virgil,
Rockstar of the Burning Abyss" once per turn."
Update #1 - 5D's LC
Mere seconds after posting this, I found that there are other leaks from not only NECH, but also the upcoming 5D's Legendary Collection. If you take another look at Virgil above, it also appears that he was trapped in an uncut sheet of card at the time of that photo being taken. #praiseleaks
You can find more of the leaked pictures in this gallery from ARG. I'll update again if I find anything else worth sharing; most of these images are a little too blurry and way too German for me to read and interpret on my own.
Update #2 - NECH Sneak Peek Promo
Just found a quality picture of this:
Update #3 - Even more leaks than before
The Ygorganization has decided to post an article that explains the leaks in-depth. I highly suggest you all check it out for things like specific listings of each card spoiled and other things not mentioned here due to my lack of willpower. Sore throats and apathy will do that to you, argh.
Some of the more important things covered include two new Nordic cards in LC05, the rest of the Secrets in NECH, and the upcoming release of Santa Claws to the TCG, presumably in the 2014 Adventkalender. Seriously though, I wonder who's on the inside at Konami and decided to spill these things?