If Tufte's article impressed/interested you, check out his two books Envisioning Information and Visual Explanations. I bought them and was amazed at their quality and insight.

The Byrne piece in the same Wired struck me as not necessarily the point to Tufte's Counter(Power-)point, but a traipse through ppt's art-technique.

Also, a comedian who does ppt stand-up comedy is Don McMillan, http://www.technicallyfunny.com, who does great geek comedy. I saw him at QuakeCon. Good, good stuff.