Ask any good filmaker out there.  When someone sets out to make a movie, there is the one you write, the one you shoot, and the one you edit.  The movie that is edited never turns out the same as the one you set forth to make. So yes, editing is important. But only to a certain degree. If you don't have footage to stand on, then its a fucking light show! No mas.  I personally think Dave nailed it on this trailer.  There is such a thing as an overedit. In my humble opinion, some of the trailers out there this season were edited 'Bruckheimer style' rather than 'Scorcese style' (he still cuts his movies by hand), allowing you to actually enjoy the beauty of the footage.  but that's my opinion, of course I could be wrong.
Cinderella Story. Comin' outta nowhere!