Anyway, I've been wondering about those 2 Nidavellir doors. You know those paintings of Ice Giants fighting Dragons? Plus, the main boss is Jotun. Looking at Norse Mythology on Wikipedia, one of the 9 'worlds' in Norse Mythology, one is called Jotunheimr. Grizzleheim-Jotun? So this may mean the Nidavellir doors may hold secrets of the Ice Giants, and I'm guessing we'll learn about their past and their fights with Dragons. Oh, I forgot to mention Jotunheimr is a world of Rock and Frost Giants. It all sort of makes sense.
Now, here's the explanation of that Rainbow Bridge and Spiral Tree.
Bifrost, the bridge, is a burning one guarded by Heimdallr, pictured above. It reaches between the world of humans and gods. Heimdallr is guarding it from Jotnar, a race of nature spirits with superhuman strength, they are also called Jotun(n) and are giants from Jotunheimr, which further shows how the boss Jotun in Nidavellir got his name, a giant grendel as he is. Here's something else I found - "In Norse Mythology, Nidavellir (Dark fields) is one of the Nine Worlds and home of the Dwarves." Now, you may remember Grumlik, a small grendel who just sits there in Nidavellir. Whats his purpose? I suspect the giants of Jotunheimr took over Nidavellir, and Grumlik may need our help to take it back for the dwarf grendels in a future quest. No wonder I picked the school of Myth ;).
Pic of Niohoggr, a giant who knaws at Yggdrasil's roots (I'll get to that soon). He's a dragon, who, for all I know, just knaws at this huge World Tree's roots. So, did the Jotunheimr fight him? Is that the Dragon in the picture battling with the Frost Giant? I take it the Rock Giants look like Jotun, and the Frost ones like, well, Frost Giants. Maybe Niohoggr was a protector of Nidavellir of some sort and lost the battle? It's all very confusing.
First thought: Bartleby. I'd bet Kingsisle based Bartleby off Yggdrasil, as Bartleby co-created the worlds and holds the Spiral/World door inside. In Norse Mythology, an event occured called Ragnarok. The fate of Yggdrasil and many giants were here, and the world began anew. Nidavellir is a brief reminder of the Norse past, I suppose, ruins still holding from the Jotun's invasion and Ragnarok. What conclusions can you draw? Many other MMOs are based off this kind of stuff, and this is how I think Wizard101 is tied to it.
In conclusion, the 2 Nidavellir doors could be the ghosts of the Ice Giants and Niohoggr, waiting for someone to release them, and I suppose all those useless NPCs in Northgard plus Grumlik -a native dwarf of Nidavellir- may hold future quests for us to uncover Nidavellir's past. Maybe we'll fight that Ice Giant and release Niohoggr. What about the midget bears? Are they part of Nidavellir? Who knows? Its in the hands of Kingsisle :)