Board Thread:General Discussion/@comment-3123266-20140303175822/@comment-3123266-20140307195810

The Tesseract is confirmed to be Space stone according to Kevin Feige. However, there is no known confirmation that the Aether is the Power stone, only an Infinity stone. The Tesseract has been a mixed bag in MCU. From MU perspective, it is not strictly a space gem because it also generates "power" for the Red Skull and changes Hawkeye's "mind" via Loki's Sceptor.

It may due to lack of foresight from the MCU team. One way for them to reconcile this, is to tie the power of gamma with space-shifting. The Hulk may have been created when Banner used the Tesseract to as a substitute for Vita-Rays to activate the super-soldier serum. While "darkforce" was not mentioned in Thor 2, the term "dark force" was used in promotional materials.

Anyhow, it's just theory. We'll see how this goes.