When someone brings up Avalon, I inevitably gush about how it will transform advanced desktop visualization from a dark art into something very accessible. I’m surely most like an evangelist when I get carried away about the creativity it will unleash.
If you work in interface design or information visualization, you've probably come across Edware Tufte. His books The Visual Display of Quantitative Information and Envisioning Information should be on every reference shelf. Through Chris Sells (who had the good fortune of spending a day with Tufte) comes the story of Sean Gerety's Avalon implementation of Sparklines, which is one of Tufte’s many elegant data visualization concepts.
In the spirit of Tufte's clutter-free, elegant design, let me offer a couple of other things I’d love to see implemented in Avalon.
[Humble Addendum: When I was finishing my Master’s thesis on computer learning, I drew great inspiration from Tufte's books when I was trying to visualize different representations. However, there’s a big gap between believing in his design principles and being capable of applying them – and I freely admit that he's given me a lot to aspire to ;) ]