I can't imagine a blurry bar chart being a good way to depict uncertainty. In charts where uncertainty is an important value, it is often the most important value, and needs a more granular approach than a blur.
Also, the main example in the article, of the Guild Wars 2 visualization, is very difficult to read. The painterly filtering on the bar chart makes it very difficult to interpret, and nesting unrelated pie charts within each other is a bad idea.
Charts made of concentric circles are usually sunburst charts, showing hierarchical or parent-child relationships between tiers of data. For example: http://www.jasondavies.com/coffee-wheel/
I completely agree about the blur - it's not a great example of how filters could be used to encode data (but it was the simpliest one to imagine and trivial to build). I could imageine blur being used to visualize concepts like probability, where showing the general shape of the distribution may be more important than the specific error range - e.g., like in http://www.velir.com/blog/index.php/2013/07/11/visualizing-data-uncertainty-an-experiment-with-d3-js/. It's not perfect, but to me it does a good job describing the data in a concise way and describing the concept of probability. If you have ideas about how filters (not just blur) could be used as another dimension (like how color or size are used), I'd love to hear it and update the post.
The guildwars visualization can be critiqued and has many flaws (I'm also not a designer). It's a bad example of good data visualization. It was really just an exercise in data art and largely an experiment with filters; with the goal of reaching as many GW2 players as possible (it succeed in that). Unfortunately, a sunburst chart / radial treemap would not have worked because of lacking data, and I agree it's nearly always a bad idea to nest donut charts (imo, using a pie chart at all is usually a bad idea, and donut charts are an absolutely terrible idea).
Thanks, I appreciate the feedback!
This would give Edward Tufte the heeby-jeebies.