thenammagazine
Super Freak
For the best that it follows Avengers IMO. Moving the Thor/Loki story forward is a lot more important than using a whole movie to explain why and how Thor showed up in Avengers (which they could either do in a prologue if relevant to the new Thor film, or explain later in flashback or exposition in a few minutes).
Honestly, I'm of the opinion it was covered in dialogue already.