Smashing Magazine explores single-page websites in an article today. It’s definitely worth a read. They look at quite a few examples of varying content and show what works and what doesn’t. I think it’s definitely a challenge to design a website that way, and should be used only when appropriate.
I love the example of the UK Energy Consumption site with a bunch of interactive well designed infographics. I like the movements between sections and the animations are not overdone.
Single-page websites are best for storytelling, if you can’t make the purpose of your website into a story (in concept, not always literally), you probably shouldn’t use scrolling as main navigation. The clothing store Ballantyne describes their company/clothing as you scroll down the page. Smashing Magazine mentions how the images don’t always align the way you would like them to as you’re scrolling, which I would certainly agree with. Though the middle column going a different direction than the two outer ones creates an intriguing effect.