Thanks to the folks of moviestinger now we have the full description of THOR's Post-Credits Scene
Here we go...
------------------------------------------------------------------------------
We see Dr. Selvig (Stellan Skarsgard) meeting with Nick Fury (Samuel L. Jackson), who is standing in front of a table with a large metal case on it.
They discuss the latest discoveries that Selvig and his team have made in relation to alternate universes and Fury asks for his advice in regards to the contents of the case: the Tesseract/Cosmic Cube. When Selvig asks what is it, Fury responds that it is a source of immense power. The camera pans back to Selvig, and a reflection reveals that Loki (Tom Hiddleston) is in fact now possessing Selvig.
Loki/Selvig responds: ”That’s very interesting…”
-------------------------------------------------------------------------------
This Isn't What I Expected but sound cool