I found Thorin to be a little underwhelming personally. I'm not in love with the art and his starting threat is quite high. Stats are good but his ability most likely wont come into play until the 2nd turn.
While he combos well with Dain (well what dwarf doesnt…) I think he'd excel best if it was those two plus Dwalin. The blue sphere gives you access to Galadhrim's Greeting plus Dwalin alone can lower threat. Quest with Thorin, Attack with Dwalin, Defend with Dain. Using blue also gives you Ever my Heart Rises which u can give to Thorin to be able to take advantage of his two best stats both Questing and Attack. Dunedain marks can be used on Dwalin to ensure you kill the orcs and lower your threat.
Love both the new Gandalf and Sting. You can just abuse Gandalf in a deck using the new Aragorn or Glorfindel and Sting is just super powerful. Artwork for both those cards is fantastic as well.
Gotta agree with lleimmoen on the Green Dwarves, they add as much as the blue will.
You DID take the words out of my mouth for my thoughts on Thorin, though. I wasn't blown away, to put it mildly. Artwork wasn't at the level as recent heroes have been. And since I won't run him with Dain (more in a second), his gametext is only kinda…. meh. Why not with Dain? Realistically, because I love my green AND blue additions to the Dwarven deck. Running two high-threat leadership dwarves in a single deck borders on near absurdity (apologies if anyone thinks that too strong a term), for a number of reasons. I will not go so far as to say it CAN'T be done… lol… just don't see the logic. To do so means you:
1) Give up either a green or blue hero to draw in the much-needed support from those spheres (sorry Red, as always you are relegated to my 2nd dwarven deck). So now you're adding Songs to your deck to bring in those other allies/events you need from that third (or fourth if you want the red) sphere. Again, YES it can be done, it just forces you to raise your card count OR drop other cards that are valuable to your synergy. No bueno.
2) Start with unnecessarily hight threat, forcing you to use Dwalin (and I do, but I will admit his threat reduction response doesn't trigger as often as you might hope sometimes), or to include more threat reduction in your hand (or hope to high heaven you keep pulling Gandalf and Sneak Attack throughout the game). Again, starts messing with your synergy and count.
3) On the plus side, Thorin's ability is perfectly suited to Dwarven themes in the game…. sheer numbers. You can get a good number of them out for cheap and early, and getting an extra resource is always welcome. However, you can gather that extra resource by simpler means (Steward…, Zigil, etc…) that are most likely already in your deck (please tell me they're in your deck… lol).
4) Another plus, his willpower and attack are great (and with Dain's bump, puts him up there with the Holy Grail of questing, Eowyn). And since none of his gametext is tied to specific phases (questing, defend, attack… like Dwalin, for instance), he really becomes a "utility" hero…. he can be used for pretty much anything. Yeah his 1 defence doesn't do anything for him, but with solid starting HP, he becomes perfectly suited to team with the red dwarves for fighting…
So what this means (I don't claim that everyone else's approach should be the same) is that Thorin will be a perfect fit as the "leader" of a second dwarven deck that can be played alongside the first (led by Dain). This gives him the best of both worlds. Pair him with a red or two (or Gloin), and create a minion-slaying gang that can keep the pressure off of Dain's questing crew…
Of course, this all could change based on Orcrist's game text does for him…