wingsandsword
Legend
Depending how closely they adhere to the comics, the Tesseract is not Asgardian technology. It is a renamed "Cosmic Cube" - renamed to avoid the cheese factor, I assume.
In the Marvel universe, several civilizations have created Cosmic Cubes. AIM (of Red Skull fame) made one by accident. The Skrulls (the Chitauri of the movie are the Ultimates-line version of Skrulls) also made one, as did others - Asgard notably *not* having made one in the main continuity.
I know the Tesseract is a Cosmic Cube, but in this continuity it seems to be of Asgardian origin. Besides Thor and Loki treating it as such, the Red Skull in Captain America referred to it as "The Jewel of Odin's Treasure Room", so if it's not Asgardian in creation, it is apparently believed to at least previously belonged to them and they are how it got to Earth.
The Marvel Cinematic Universe seems to be a blend of Ultimates and main Marvel continuities mostly, with a few new elements thrown in here and there. Sometimes because one sounds more cool or would look better on screen, sometimes for legal purposes.
For example, Marvel can't have the Skrull appear in one of their movies. The movie rights to the Skrulls are tied up with the Fantasic Four, which along with Spider Man are the two big-name Marvel licenses they don't have in-house anymore. However, they didn't license away the Chitauri version, so Chitauri replace Skrulls in the Cinematic continuity
I don't think they are letting themselves be tied down by any prior comic continuity. It's probably best to treat it as a separate world in the multiverse. Mainstream Marvel may be Earth 616, Ultimate Marvel may be Earth 1610, we don't know the number for Cinematic Marvel.