Except that this is a gameplay trailer. Not a teaser, or a release trailer, something that's actually meant to be indicative of the game - so you can be sure that while there are many placeholders left, they'll have steered well clear of them for the trailer. It's not good marketing to show things that don't work yet.
You might think that yes, but if 70-80 percent of the game is full of placeholders, they're kind of hard to avoid. its not at all indicative of what we will get at the end of this year, and they're not going to start polishing stuff just to release a trailer. Sure, they'll try to make it look as good as they can without detracting from development time, but the trailer was great enough that those few things aren't going to bust it. The naysayers and people who pick apart this stuff with little understanding of what is really going on are very much in the minority, I can assure you of that. This trailer was class-A marketing material as far as game trailers during development go.
Would you guys be happier if they didn't show us anything at this point? I mean, everyone has been dying to see something, and now that they give it to you, its nothing but complaints. What you all are asking for is that we not see anything until its the final product, and that from a marketing standpoint is not good, because there wont be anything to show until a month or so from release.