What was shown during the Super Bowl is the teaser. The movie isn't out for another 4 1/2 months. Now's not the time to be promoting it, especially with the SW hype machine gearing up. It'll get lost in the shuffle.
Spielberg knows how to market a movie. I trust we'll see another trailer pretty soon, but in theatres first. There's been so much hype surrounding the movie, they aren't even necessary. I mean, Episode 3 is out almost an entire month prior, and there's only been 1 teaser trailer, and it has yet to hit television.
There's a good number of people who don't know about the movie yet (my dad for instance, he saw the commercial today and was like "Oh wow, they're remaking WOTW? That should be good").
The superbowl is the perfect time to advertise anything. No matter how many people know about it, there are always some who don't.
I thought the clip they showed during the superbowl was perfect because it was enough to get people talking and peak interest, but didnt tell much more about it. I think this should be a good one.
Also, the trailer didnt show any of the aliens, which would of sucked.
It's a Spielberg movie with Tom Cruise and eneormus budget and a sci-fi cult classic. So, I personally dont think it will get lost with Episode 3. It might not do as well, but it will still sell gazillon's of dollars.
Spider-Man came out at the same time as Episode 2 and it did better, so anything can happen.
Of course they didn't show the aliens. It would ruin the surprise. They did the same thing with Godzilla and Independence Day. They NEVER show the monster in a trailer.
The reason it wasn't longer is that it costs many millions of dollars just for 30 seconds of time during the Super Bowl. If it had been 4 times as long? The movie already costs more than any other movie ever made.