First tv spot released, it's up on youtube, at deadline, and at theonering.net
AS to the running time anyone who thinks you can tell a good version of the Hobbit in two and a half hours in really not paying that much attention to the book.
The book is short because there is almost no dialogue and the writing flies through the narrative.
If you look at the time it takes Tolkien to write passages that are similar between the two works, LOTR basically takes three to four times the length to describe similar events.
Though Bilbo and Frodo's quest are different, I believe they take the same amount of actual time once they start. And thats without ever addressing whats up with Gandalf and the larger events in the world.
Now they could have filmed a version without much real dialogue, they could really compress the time, or they could spend up the motion of events like animated films often do, but that would certainly be a different type of movie. From the get go Jackson said he wanted the Hobbit to be set his take of the Tolkien universe. Ie be done in a style similar to LoTR.