I've been working a lot on editing/revising lately, and it really is the most important step in writing.
It even is in movie making. Take this Star Wars clip, for example. Once it's edited, it takes on a whole new meaning.
In one of my film classes this past year, we talked about not only the significance of editing, but who does the editing. Directors/producers/writers NEVER EVER EVER edit film (unless maybe they can't afford to hire an editor, but in that case they're probably making a low budget documentary or something to that effect). This is because they are never able to distance themselves from the piece of work; all they see in a clip is how long it took the actor to cooperate, or how much money they paid to get a certain lighting effect. An editor will see the clip and, if it doesn't aid the story of the movie, they'll cut it without a second thought.
That's why, in writing, it's so important to have betas, or critique partners, or whatever you like to call them. A good beta will tell you the honest truth about your writing so that it's stronger and more effective.
In conclusion: yay for editing and betas! My betas make my book kick butt.