Bioware's Marketing & PR really need to figure this out soon. Whoever is holding things back needs to realize if this keeps happening eventually nobody's going to care.
For the new OP, easy content strategy to build excitement and actually help people understand the story behind it:
1) Reveal a boss each week / every few days and include how they tie into the story. You don't have to give everything away, just connect the dots a little bit.
2) A few cryptic screenshots of the gear.