Yes I think they do.

It has to be positive marketing. Even when the clip is being made fun of. It falls under the "any noise is good noise" philosophy.

No, I don't. Most major Hollywood studios are all about control. If they can't control it, they don't want it. For example... The technology for DVD was invented several years before it showed up in the marketplace because the Hollywood studios delayed its introduction until region encoding was included in order to maximize their overseas profits. Blu-Ray has a lesser form of region coding and HD-DVD had none because the studios found out that their profits didn't change that much because of its inclusion in the DVD specification. You have to realize that most of the people making the decisions in Hollyweird are in their late forties/early fifties and have no idea how technological advances are going to change their industry. So their first impulse is to stamp out anything they don't control. Then they'll set up a study to determine how to use the new tech to increase their profits. By the time they've figured out what to do, the technology is obsolete and there's a new thing on the horizon that they can't control. So the process starts all over again. Just think how the RIAA fought against downloaded music. Even though studies suggested that the people downloading were actually buying MORE music, they refused to consider it. Then along comes Apple and makes money at it. All of a sudden there are thousands of legal places to download songs and the industry is wallowing in the cash. If the studios can't see a cash profit they won't like it. Of course they will still release trailers that way, because it's good viral marketing. And some of the "leaked" footage is deliberately leaked to promote a film (usually one they don't have as much confidence in), that way they still have control. Hope this helps.