I love d3. Mike Bostock does great work and the flexibility of the d3 library really makes it super-powerful. The fact that it doesn't work lt IE9, however, makes it unusable for me at work. Most people on corporate networks (at least in my experience) are running win xp with ie8. Once we move everyone to win7 I should be able to start pushing out some great analytics based on the d3 library. looking forward to it!