My random thoughts on these sets:
Yippee! I've been wanting Vikings for years. I'm not overly thrilled on the Bionicle-y monsters, but oh well. I hope that at some point we'll get Odin, Thor, Valkylries, Valhalla.
Helms - I know it's not historically accurate, but my own LEGO castle universe has always been more fantastic, and I love the horned helms. It looks like there may be two different ones, because in 7015 and 7016 the horns seem shorter than in 7019. Is it possible the horns are removable (since they are a different color than the helmet)? If so that could be good for using them in brick-built-beasts without cutting the old horn piece.
Weapons - I see a new single-bladed axe in 7015 and 7016, and a double bladed one in 7017 and 7019. Again the axe heads might be seperable from the shafts, since they are different colors in 7016 (perhaps that is a new axe head with a 4-long bar (lightsaber blade). Also the one in 7017 appears to have[urlhttp://www.bricklink.com/catalogItem.asp?P=4095]this bar[/url], as you can see the little bump near the bottom. There's also a war hammer in 7019, for Thor customs. Of course all of those new patterned shields (two types, one flat, the other convex) are very cool. Also, do we have the spears in light gray (or blay) already?
Beards - very cool. I was already planning on doing a run on Red Bean's beards (still am), but am looking forward to these as well, so that I can have a large force of dwarves. I guess I'm going to do the Hobbit after all.
The Ship - this is my favorite set by far. I'm actually not all that thrilled by the larger fort set (since I've got Fort Legorado and could easily make something similar). I'm a bit apprehensive about how juniorized the actual boat hull will be. I assume it will be in three pieces like the pirate ships. I love the sail, btw. This is probably the set I'll get, and then pay Bricklink mark-ups for the figs and accessories from the other sets.