Actually I think the "2.5" trailer was just a rolling demo-reel they made for the GamesCom booth. They just put the 2.5 release on the end for the release. That takes like 10 minutes in a video editing suite like Adobe Premiere.

Taxman

"Any group is weaker than a man alone unless they are perfectly trained to work together."
- Robert A. Heinlein, Starship Troopers