When Hulk was at battle in New York, Hulk never really paid attention to what caused war in first place. Hulk didn't show up in fight until Hulk had to smash giant snake thing. Hulk told by Man of Iron that they were fighting over magic cube.
Hulk was thinking. Did any of you ever think that the Tesseract Cube is similar to the AllSpark from the first Transformers.
Hear Hulk out.
They're both sources of ultimate power. They both wanted by an evil villain (Loki and Megatron), and they both could destroy Earth if fall into wrong hands. See similarities?
What you puny humans think? Could the Tesseract Cube be copy of Allspark from Transformers (well, that incarnation anyway)?