The interesting part of the piece is where he quotes Saul Williams talking about the difference between hip hop and slam:
"The difference between the poet and the M.C. is that the M.C. is by definition a master of ceremonies," Williams explains. "If you aim to be the master of ceremonies, then you have to play the role of the oppressor. You have to be in control, you have -- to use a hip-hop slogan -- 'to act like ya know, son, you have to act like ya know.' Whereas the poet is allowed to be introspective, allowed to raise questions -- is allowed to say, 'I don't know, I wonder why, I wonder what this means.'"
[...]"The poet is allowed to be vulnerable," Williams continues, "whereas, with M.C.'s and in hip-hop, vulnerability is a sign of weakness. And so it becomes less and less real, less connected to the true nature of humankind. The further out we go on the tip of invulnerability and being hardcore, the less we can show a soft side."
Here Saul Williams is talking like a poet, not a slam poet. So perhaps the moral is that slam poetry isn't some revolutionary force changing poetry, so much as it is a revival of the verbal aspect of poetry that became more latent in the modernist era.