The Advertising Lab blog points out a possible problem with Ballroom style presentations, towards the bottom of this post:
We used to spend hours fumbling with PowerPoint templates and animations and slide transitions. Today, we spend hours coming up with clever one-liners and raiding Flickr and stock image banks in search of the perfect generic photo in high resolution. The result is pretty much the same, only now the image-heavy and word-light decks can't even stand on their own without the presenter to provide context.
How quickly things move; it was only about a year ago that we were celebrating the triumph of the Ballroom style presentation.