Great presentation by Susan Weinshenk, "The Brain Lady", at the Converison Conferene in Chicao a month ago. My Notes are here: http://www.atlanticbt.com/blog/conversion-conference-live-blog-monday-june-25-pm/ .
Conversion is about connecting websites to WHY people act one way or another. Susan is pioneering new science of design, design influenced by neuromarketing and focused on connecting websites to people.
She knows the keepers o the website design flame are grpahic designers so she creates great content to help designers understand their ultimate customers (those who actually use the sites they design) better.
If ask me for an example of the best design for a website I would say the one that converted better. Everything else is conjecture, specutation, damn lies and statistics :).