Jorge Cham of PhD Comics makes the best possible information graphics. Illustration seems antiquated in the data viz age, but treemaps and big blinking interactives don't even approach the engagement and explanatory value that come out of his Wacom. His comic infographics also translate beautifully to animation: the above is a screencap of his drawing process, overlaid with commentary by the grad students he interviewed. It doses the information at a comfortable pace, gently demonstrating to the viewer the importance of stellar physics in understanding the universe.
Data viz can explore trends but can't approach illustration's natural fit for relating concepts. This becomes glaringly obvious when the topic is completely novel to most people: hard science. Let's stack up the fine fists vs. the number pukers.
The neurology graphic above, also by Cham, took the infographics gold at the NSF's 2009 Visualization Challenge. How'd it beat out a big pile of charts? Accessibility. Illustrated infographics speak to us in ways that abstract charts never can; people just like comics. They're intuitive, easier to get into than big colorful visualizations. They literally speak our primitive hindbrain language: pictures! Little people! That looks like me! I'm listening! Way more fun than a big awful tag cloud! What the hell was that trying to tell me anyway!
In contrast, this science graphic published in the New York Times is a woefully bad fit for a lay audience, using a visualization that works great in the bioinformatics lab but falls flat in a broadsheet. I went so far as to ask the New York Times graphics editor to explain this to me, but he couldn't tell me what this pile of "epigenetics + Circos = ???" was even about.
I'm all about big, impossibly dense graphics, but most readers want nothing to do with this. They want to see the jewelry. Don't hand them the pan and point to the river. That's an awful metaphor but I'm unhealthily attached to it. Anyway in conclusion, when it comes to disseminating information I'll always prefer the skilled illustrator over the R munger. Maybe that's the David Macaulay nostalgia talking, but this just works better.