... and you know what I realized? This movie's dumb.
I mean, sure, it's very nicely done effects-wise. There are some great pieces of dialogue, good character moments etc. The movie is certainly entertaining on many levels... but the plot itself? It's dumb.
The whole affair is that Loki strikes a deal with the Chitauri aliens: they will conquer the Earth for him and he will give them the Tesseract. For this to happen, he needs to get the Tesseract, create the portal-making machine and fire it up. Quite straight-forward. It leads straight from the opening skirmish with Loki to him opening the portal in New York.
Sooo... what was the point of him getting himself captured by SHIELD? Maybe I misunderstood something, but I got the impression that Loki actually wanted to get captured in Vienna. But, if so, what was his plan? What did he achieve? Sure, that plot diversion gave us the cool Helicarrier battle and all, but what was Loki's goal? He didn't achieve anything. He didn't set back the heroes in any way, his real plan didn't depend on being captured in any way... So why did this whole segment happen at all?
It's kind of annoying. I really want to like "Avengers" as a movie, but it's a bit hard. Plot-wise, this movie is quite bad. Couldn't the people behind this movie come up with something better...?