Julia seems promising, I haven't used it on a real project yet though, but I really like how easy it is to do data visualizations in the browser with Clojurescript and don't see Julia really having an answer for that.
R's ggplot2 beats Incanter (or anything other charting library) by a large margin in its excellent mix of conciseness and power, but I find Quil pretty nice for animations (superimposing data on geographical maps, for example).
I keep an eye out for new charting libraries coming out for clojure. Last two I spotted were vizard from yieldbot (https://github.com/yieldbot/vizard), and what seems to have only been a small project, xvsy (https://github.com/dvdt/xvsy)
I have to say, Quil is the least Clojurey library I have ever used, and I find it very, very primitive. There's definitely a huge gap for a project built with idiomatic Clojure bindings that can handle both nice graphical stuff but also stodgy charts, with basic stuff like annotation layouts etc. I think something that could work really well if anybody finds the time is a port of G:
https://github.com/dvdt/gyptis
It is a nice wrapper around vega. Using that now.