"He'd willingly make rubble of the earth / And swallow up creation in a yawn"

Although I've read The Waste Land before, I have always been taught that it is a poem expressing the so-called "'disillusionment of a generation,'" an idea which Eliot himself calls "nonsense." Because of New Criticism, among other things, we have come to expect to extract from a poem one tiny nugget of meaning which can serve as summation of the whole. With The Waste Land, such a paring down is impossible. As Misty wrote in her blog, we could easily devote an entire course to the reading of the works to which the poem refers in order to approach the poem.
Without being reductive, it has been difficult for me to arrive at a satisfactory meaning. I was thus encouraged by Eliot's own approach to a difficult work in his essay "Ulysses, Order, and Myth." He writes, "All that one can usefully do. . .is to elucidate any aspect of the book—and there number of aspects is indefinite—which has not yet been fixed" (175). I wouldn’t dare to say that any portion of The Waste Land has gone unexamined (has "not yet been fixed"), but I think the idea of attacking one "aspect" at a time is particularly useful to attempt understanding the poem.
I attempted to understand the poem's positioning of boredom ennui as the ultimate sin. Brooks's argument that the last line of "The Burial of the Dead" taken from Baudelaire is meant to complete "the universalization of Stetson begun by the reference to Mylae" by showing that "Stetson is every man including the reader and Mr. Eliot himself" seemed to me an incomplete interpretation. I think, in light of the Baudelaire poem "To the Reader," that this line is an accusation—a universal one, yes—of the worst of sins, which is not lust necessarily, as I think Brooks would argue, but boredom. Lust functions as a result of boredom—it is a symptom rather than a cause. Lust is evil, but it is not the root of evil.
In the poem, this boredom as the worst of sins is most apparent in "The Fire Sermon" where the typist allows herself to be subject to the clerk's lust simply out of boredom: "The meal is ended she is bored and tired" (236). If lust were the driving sin of the poem, we could expect more emphasis to be put on the clerk, but once the act is over, he disappears. It is the woman and her ennui that are subject to the poet's censure. In calling her the "'lovely woman'" who "'stoops to folly'" (253), the poet seems to suggest that she ought to kill herself as the subject of Olivia's song should, "her guilt to cover." Instead, the typist "puts a record on the gramophone" (256). Later in the section, the same type of relationship occurs between Queen Elizabeth and the Earl of Leicester, and again, it is the object of lust who bears blame rather than the man who lusts. She is the one who can "connect / Nothing with Nothing/ la la " (301-303). The "la la" seems to be a restatement of her boredom, a restatement of the diversion from boredom that her relationship to Leicester was. While he weeps, she remains bored, indifferent. The following burning of St. Augustine, which eventually leads him back to salvation, is something the Queen figure cannot experience. Neither the typist nor the Queen actually do anything in this section—they allow things to be done to them, and this calls their very existence into question. As Eliot writes in his essay on Baudelaire: "'So far as we are human, what we do must be either evil or good; so far as we do evil or good, we are human; and it is better in a paradoxical way, to do evil than to do nothing: at least, we exist'" (qtd. in Brooks 186). The idea of boredom and the resulting inaction as ultimate sin makes sense in light of the "aboulie" (inability to act) from which Eliot suffered during his breakdown and his writing of the poem.