People often ask me how many bullet points is enough for their presentation. My answer is always the same: as few as possible...how about zero? In general, the more bullets your PowerPoint has, the less effective your presentation will likely be.
Over at BeyondBullets, Cliff Atkinson has a post that links to a great little article and asks the question, "As an audience member, do you think things are getting better, or do you detect a simmering sentiment of frustration?" I am an eternal optimist, but PowerPoint presentations are, I am sorry to say, not getting better, at least not in Japan.
The "traditional way" of doing PPT (long, boring, ugly, text-filled snooze-fests) has been going on for so long, it is in a sense part of "culture." That is, part of corporate culture. It is simply "the way things are done." And one fact about culture is that it is slow and difficult to change. People are comfortable with the way things are done. (In documents, how many people put two spaces after a period and swear this is correct, for example? — Unless you are using Courier font, one space is correct, by the way).
Here in Japan, for example, young employees entering the company will be taught, at some point, that when they do presentations with PPT they should put a minimum amount of text in each slide. Good advice, right? BUT, a "minimum" would be something like 7-8 lines of broken and complete sentences. The idea of having one or two words (or -- gasp! -- no words???) would be a sign of someone who did not do their homework. A series of text-filled slides with plenty of "chart chunk" shows that you are a "serious employee." Never mind that the audience is bored (or that the exec board does not really understand your charts). Looks complicated...must be good.
I have a shelf full of presentation books in English and Japanese. All of them say "use a minimum of text." Most of them define "minimum" as being 6-8 lines of bullets. No one can do a good presentation with slide after slide of bullets, not Steve Jobs, not Richard Branson, no one. Bullets are for documents and only occasionally effective in multimedia.