I may be late on the uptake with this, but did it occur to anyone else that the character speaking at the beginning of Avengers is Thanos (to Lady Death)
"The world will be his, the universe will be yours. And the humans, what can they do, but burn?"
I had originally attributed this quote to the Other, speaking to Thanos, but the voice is different from the one used in the Loki scene, also both the cloaked figure who comes in and kneels (at the beginning) and the one who hands Loki the scepter only has 5 fingers not 6, so not The Other. ( The Other is in the end scene though)