There is sweetness in Sendak's work, but it is rich and complex and distilled from rougher stuff; it is molasses in a sea of aspartame tablets. There are glories in the art and the text; few of them rise from what you might think of as comfort. The world and its possibilities; adventure, yes, but danger and separation and darkness... we "sail off through night and day and in and out of weeks," armed with curiosity and love, clad in a funny suit with which to blend in with the bewildering creatures we encounter.
Maurice Sendak perceived and expressed, in the most singular way, the complexity of our strange and crosshatched world.
In a less navel-gazing vein, here's Sendak's appearance on The Colbert Report a few months back. He was extremely Sendakian to the very end.