Great writing needs great editing

I've been reading Wolf Hall (winner of last year's Man Booker prize) and couldn't help wondering about the (relatively) unsung heroes involved in putting it together. It is a beautifully written book, and it must have presented a unique challenge to the editors and proofreaders who worked on it.

I have no insight into precisely how they worked, but, to my mind, they must deserve credit for striking that difficult balance between making sure the text is correct and not interfering with the author's style. There are one or two instances, for example, in which an over-zealous proofreader might have replaced the odd semi-colon with a comma.

Now, this particular book might have required lots of editing or none at all, for all I know, but it did make me wonder. How many great works of literature have seen the light of day thanks to a light editorial touch? And have any ever been stifled by an excessivley heavy hand?