LOKI GETS A CO-HEAVY FOR THOR 2
I actually liked Loki better in Thor. He has more presence, has a real story arc, there's a hint of tragedy (learning about his true nature, which is probably what has driven him crazy by Avengers), and in the beginning he is an ally of Thor. In Avengers he's full on Bad Guy. He's only got one "moment", when Thor pleads with him to help the Avengers stop the aliens and you can see Loki thinking about it, then saying "naw, it's too late".
In recent interviews, Feige has implied that Loki probably won't have a main role in Thor 2. Dude is taking the backseat this time 'round.
As for Mads? He's good in everything he's in, even if said project isn't always stellar (i.e. Clash of the Titans, King Arthur, Three Musketeers, etc.). Another great rogue for the Marvel Movieverse! Hopefully as Surtur!
Also, do people REALLY think Marvel is going to blow their Thanos wad in a Thor sequel, as opposed to Avengers 2? I hope not. If they do, I think they are going to be very disappointed.