At San Diego Comic Con and the Disney Parks Blog, Disney officially announced that a new Guardians of the Galaxy inspired attraction would be taking over the Disney California Adventure version of Tower of Terror. The new attraction is called Guardians of the Galaxy Mission: Escape". The attraction is expected to close in early 2017, reopening in Summer 2017. A video explaining the attraction can be found here:
The confirmation regarding only the California version of the Tower of Terror is an indication that Disney will not be making the same changes to the Hollywood Studios version of the attraction. While not confirmed, this also could be a sign that the larger scale Guardians of the Galaxy attraction replacing Ellen's Energy Adventure will be the path taken in Walt Disney World. At this time, we are considering the Epcot version of the attraction as "In Development" with the "Hollywood Studios" version of the attraction as Dead.
Our full rumor tracker for Guardians of the Galaxy can be found here.