And what exactly was released for Fallout 3 leading up to E3?
Release, I said release. Not E3.
However, I don't remember seeing more than a teaser trailer that confirmed its existence before that E3. We already have more information for Skyrim (in proximity to E3) than Fallout, and the team is still working on the details they haven't mentioned yet. Several staff have repeatedly said that most of the things currently in development can't be talked about because it's all so subject to change.