Wow, what a fun chapter!
You've made things jump around the page, almost killed your computer and patience with a zoomable map, and made a supremely awesome bar graph. Well done!
In this chapter, we've animated with transitions, interpolators, and timers. We then learned the difference between explanatory and exploratory visualizations, and used interactivity to create the former. We then made some exploratory visualizations using behaviors with some of our previous projects. Things are starting to look pretty snazzy, aren't they?
In the next chapter, we'll be looking at creating a whole boatload of really pretty charts using D3's hierarchical layouts. Combining both the skills you've learned in this chapter and the next one will mean that you're able to produce some truly fantastic charts. Hope you're ready--this is when stuff starts getting really cool!