If you absolutely can't wait, Twitch user Gine22 currently has a livestream of 3rd Super Robot Wars Z Jigoku Hen running at the moment. Also, finally an answer on Gundam cut-ins?
* Update * - added a clearer and complete version of the opening demos to the article.
With some people in Japan already having a copy of the 3rd Super Robot Wars Jigoku Hen, all kinds of media from screenshots to livestreams are starting to appear...