I've been using Office 2007 Beta 2 for a week now, and I'm absolutely hooked on Powerpoint2007 SmartArt. With this cool new feature, basically, you can type in the list of bullets on your slide (as usual), and then through a couple of button clicks (insert -> SmartArt), you can convert them into sophisticated diagrams that shows interesting workflow/hierarchy/relationships between these bullet points.
For example, this is what I did in literally 30 seconds:
And what's even better is that by simply moving/floating your mouse over the various alternative template diagrams, the effect (or resultant diagram) is immediately displayed on your Powerpoint slide! How cool is that!
you can see a demo of PowerPoint 2007 here. I'm going to build all my TechEd presos this way...