Getting back on-topic, it seems from early reviews that T:TDW will suffer from a bit of the Iron Man 2 Effect, in that it will feel like a sequel for its own sake rather than really being a story that effectively advances the characters. The main plot sounds like a fairly generic sci-fi/fantasy plot with the fate of the Earth (again) at stake, with the fun of the film more in the "how" than the "what".
I loved the first Thor film and would love to see a more fantasy-based take on his universe, so I'm keeping my hopes up. I think it'll be a fun ride, but nothing spectacular. It would be great if it surprises me though.
All the early reviews have at least said Hemsworth and Hiddleston are great again as Thor and Loki, with the latter in particular worth the price of admission. But I really love all the characters in these films, even the supporting cast. The first film did an admirable job of ingratiating these characters to the audience, IMO, and I look forward to seeing their adventures continue. I find the Thor movies to be great light entertainment, in the best sense of the term.