After looking at some of the photos, there's good and bad.
So, are these FINAL products, or still Prototype show-offs for the Toy Show?
1) The castle lost the cool angled corners with windows, and instead have 45° corner pieces (are those stickers on them? They look kind of icky).
2) The castle is shorter now. The whole front is at least 1 full brick shorter, the back right tower is 1 brick shorter as well. The extra crenellations around the front towers are removed (they LOOKED cool, but other than that, they didn't serve much purpose anyway)
3) The drawbridge is slightly shorter (2 I think), and lost most of the brown tiles on top (doh!)
4) The front of the castle isn't as deep now (look at the loss of the nice arch on the left side, and the 'holes' in the rock on both sides along the ground).
5) Pointy visor is in! Woohoo!
6) The green on the BURPS out front is different (different coverage, not different color).
7) Torches are moved around, at least one is added.
I could play spot the differences all day, but does it really matter? I'm sad at the loss of those brown tiles, and I'm disappointed by the dragon. It is WAY cooler than the old Dragon-Masters dragon, but after how much I liked Nidhogg, this one is a let down.
On the Evil Fortress, the Jaw-bridge is much shorter, can't tell much else...
The carriage, still has it's 3 skele-horses! I think they don't look very good with regular minifig legs in the 'saddle' (from the Joust picture), but maybe with skeleton-legs they'll look better. Looks like the chrome scimitar is gone (those things are monstrously silly looking anyway), and a Viking-style double axe is in. Can't tell if it kept as many skeletons as it had before though.
Also a RANGE of skeleton heads. There are the new red-eyed evil ones (see the evil fortress, the rider in the wagon set), as well as lots of old evil smiley ones.
So, good and bad. Nidhogg really spoiled me for dragons though, I don't think I'll like these new ones. If only Nidhogg came out AFTER these new dragons!