ok, i will bite..
1st of all.. it does depend on what TYPE of presentation your giving.. If your just doing marketing reports or some simple statistical show, or you just need to illustate a point to the people within the company then no.. you don't need a bunch of flash.. and for that fact, you only need graphic's when called for to illustate or accentuate a point.. to help visually carry what you need to get across...
But when you want to sell something, be it a idea or product, the more powerful your presentation is, the more weight you can give whatever your selling.. and that is fact.. you can disagree all you want, but in the end, the guy that puts more time and effort into his presentation will win... and keynote is only ONE more thing to help you give either a good presentation or help you give a great one...
and yea, if all you have is flash, and your product is a lemon, your not going to get very far..
But if you take a good product - or - idea, and you have 2 different presentations.. the better presentation will go over much better..
presentations is more than graphics -- for sure.. it is ALL about HOW you communicate what you need to communicate..
BUT anything that can help you communicate better -- anything that gives you that extra 5-10% more -- will help..
and if you got a great idea, great speech, and great graphics, you will have a great presentation.
"The guy with the better presentation will win.. "