Tripsdrill has posted a new video with a few shots of the new coasters, as well as an interview with Benjamin Fischer. Since it is German the major points:
-Plans started right after Karacho was finished, the intention was to build only the suspended coaster, but during a visit to another park the idea came up to build a second coaster intertwined with the STC (Someone visited Phantasialand I guess)
-The theme for the Family Boomerang is a result of the car design, that seemingly was done before they decided about their idea, no idea why though
-The idea of the STC came from one of their creative people
The video: