Not sure why Marvel Studios is making the Tesseract a "Gem" but it appears they are. Along with the aether and who knows what else. I suppose we'll find some other items in the Guardians of the Galaxy movie.
And yes, Thanos should be able to solo that team of Avengers by himself, though I suspect he didn't just go get it because Thanos ALWAYS has his main plan concealed...
__________________ "Your mother was a venereal disease-ridden prostitute who was raped by the father you never knew and killed herself when she saw what an autistic phaggot you are.
So what about my comments made your ass so sore? Was it me calling you a phaggot? I think not." - Nemebro
Simple: he sent the pawns in first to see what type of resistance the earth would offer. Now he has a bearing on what to expect the next time he launches a full-scale invasion on earth.
"The Grand Admiral was smart and subtle, but never used his brilliance to show up or humiliate anyone.
He demanded results, but never perfection, and had amazing stores of patience for those who were truly working to their fullest ability.
It was a pity Thrawn's style of leadership hadn't spread through the rest of the navy.
If that happened, he suspected, the Empire would stand forever."
By now we know Marvel wants to do an Infinity Gauntlet type story for Avengers 3.
And since Loki is popular, Marvel finds ways to give him more screen time.
I think he may play the Mephisto type role by Avengers3. If you read the infinity gauntlet you know the role im talking about. Thanos's sidekick but scheming on the side to try to take the gauntlet from him.
I dont think there is time (before A3) to introduce Mephisto in the MCU. Loki would fit perfect, as he is already established. Also Thanos is most likely going to Asgard to get the tesseract. When Thanos gets there Odin(loki) could bow to Thanos in a "WTF" moment, before handing him the Tesseract and joining him.