Guest blogger Tod Langley comments on setting tone and foreshadowing.
I checked out your blog. I thought some of the discussions were extemely valid. One that I remember still sticks in my mind, and I try to think about it during every chapter re-write: the importance of establishing tone, scene, and POV within the initial paragraph.
You could also make the argument that the first sentence of the first paragraph is the most important of the chapter. This is especially true for the beginning of the novel, but I use the premise for every chapter.
I also like to use the scene setting within the initial paragraph to foreshadow the rest of chapter - sometimes hinting at something dire occurring later in the book.