If the Comic-Con trailer is any indication, the CGI/SFX should be polished by now. So the first full-length theatrical trailer should be set to go. Hell, WB could release the trailer with Twilight if they wanted to, but I wonder if the score is finished. Eh, I disagree. Man of Steel's teaser was perfect in setting the tone for the film. The symbolism also helped create an inspiring atmosphere. I don't know how you found it to be depressing, quite honestly. I perceived the teaser to be sentient and uplifting while showcasing Superman's humanity flawlessly. The proceeding trailer will be more action-packed though. It's Zack Snyder, after all. I'm expecting a very physical Superman with heavy Sci-Fi elements.