Prof. von Prondzynski writes in the Irish Times:
The problem now is that, all too often, the medium has become the message, and the presentation doesn’t so much illustrate the point as obscure the fact that there isn’t one. The standard approach – 36 slides spelling out all the key points, with the presentation printed out for everyone in the room – increasingly represents bad practice, as it may actually inhibit the intellectual connection between the presenter, the topic and the audience, creating an automated process of very little value.
via Time to ditch PowerPoint and embrace 'naked teaching' - The Irish Times - Tue, Sep 28, 2010.
Hear hear.