Where to start, where to start?
First, this isn't exactly a primary case of bad TTG marketing. The trailer seems to have been released early, at least there has NEVER been an "official" link from the blog.
Second, as most people seem to forget, TTG is an American-based company. They're trying hard to get the Europeans in the boat whenever possible, but it can't always be done. They got the PSN release schedule under control - mostly - which is an achievement of its own. I don't see how this can be a huge letdown if Europeans get the game a few days after. Honestly, other games are delayed for MONTHS.
Third, what I love to call "kamikaze marketing" has always been a telltale sign of, ummm, Telltale games. But it can go both ways, at your loss and in your favour. One day you might win a model DeLorean in the "insider forums", the next day you get a nice deal at the TTG Store. But as soon as your order is placed, an even better deal emerges. One day you pre-order a game and get access to an exclusive forum, but mid-season, the price of the game may drop significantly. One day, through certain circumstances, you actually get an 80% discount in the TTG store, but during the following months, it turns out that two thirds of the things you ordered were actually forever out of stock and you will get your money back instead of actually enjoying the reduced price while shipping costs to Europe reduce the remaining third to less than a real deal.
If you try not to let that bother you, TTG's marketing can actually be very funny.
"What are they going to do next??"