My presentation had too many slides. Every slide had too many bullet points. And I was able to explain too little. Well that was two years back. But over the course of my presentation making history I realized one thing - When I had too little to speak, I made a long presentation detailing every point. When I had too much to tell, I automatically ended up summarizing the work.
Length can sometimes act as a good indicator for depth with an inverse relation. If you can shorten it, it means you've understood it. Seth Godin has another interesting take on length. He says, "Shorter, though, doesn't mean less responsibility, less insight or less power. It means less fluff and less hiding", or simply more work.