I'm a bad, bad fan, not having seen it yet. I'm glad I finally did though, I really enjoyed it! Even though I'm likely the last person on Earth to have seen it, I'll stick spoilers behind the cut.
Yeah, if anyone thought they'd really kill off Loki, I'd be very surprised. I knew there was no way he was really dead -- fan protest (and revenue) aside, it's just not in Loki's character to die that way.
What I did fall for was thinking that Loki really did betray Thor once his cuffs were off. I was even going to title this post "Thor 2: Leopards Don't Change Their Spots". I had a good laugh when I was mistaken!
All in all, a very fun movie! I'm really glad I finally saw it. The dark elf plotline did nothing for me, but I very much enjoyed all the Thor/Loki interactions. I still hate Darcy though, she's so incredibly annoying.
I had to google to find out about the mid-credit scene (about The Collector). I'm new to the Marvel world, almost all of my exposure is through the movies. I'm really, really, really not sure about this Guardians of the Galaxy storyline ("storyline"? World? Plot? Universe?). I would be more open about it if not for the raccoon character. I just cannot take it seriously: