Finally saw it, and enjoyed it thoroughly. A really well-done sequel to an excellent film. Thor and Loki and Jane are particularly well cast in a wonderfully well done film series, which may well be one of the best comics-to-film adaptations ever.
I was very happy to recognise Zachary Levi as one of the Warriors Three, and was re-reminded just how great the Lady Sif and the Warriors are as supporting characters.
The one problematic element - which was, ironically, also one of the things I enjoyed so much - was that it didn't seem sure what it wanted to be: adventure/epic or action comedy (with occasional but extreme emphasis on the humour). Thor hanging up his hammer had the cinema erupting in laughter - and that happened at least three times more, which was a) great! but b) decidedly odd in such a nominally non-comedy film.
I was also very glad that I'd avoided being spoiled over one of the best throwaway bits:
A special guest cameo by Chris Evans as Loki-as-Cap!
Natalie Portman is wonderful, and was also given the chance to point out clearly that, while Thor was rightly unable to come back to Earth, he nevertheless made it down to NY for The Avengers... without stopping by to see her..! Apparently, though - and I understand where it's coming from - there is criticism in some quarters over Ms Portman's Ms Foster being given the role of a ludicrously intelligent scientist who gets plenty of chances to looks comically baffled, but very little chance to display her intellect.
Clearly London is offering tax break to Marvel films - F4 2 was at the Eye, and now Thor hammered Greenwich and ate Shreddies!
There was even a 'hidden Mickey' when the worlds aligned. Interesting...
The post-credits sequences were in order: great comics-fanboy fare; touching and important; and
utterly hilarious!