Is it really necessary to have Raphael as a dependency for such a simple widget? Just seems like overkill to me.
I recently did a similar widget for a project of mine, using canvas (I understand SVG has better compatibility than canvas) but either way would be nice if I wanted this widget that I wouldn't have to include Raphael as well.
Raphael isn't just SVG; it's a vector library that can use SVG as a backend. It also works on IE back to IE6, using VML.
So if your goal is "SVG" and/or you only need to support modern browsers, then use SVG, it's great. If your goal is "vector graphics" and you need to support every browser made in the past 10 years, use Raphael.
It's totally possible to create a simple svg file in different ways. I'd think of this posts headline as 'Showing the power of svg by giving you a nice albeit simple graph element (in this case, generated with Raphael)'.
I work on a web-based instrumentation and visualization system that uses SVGs.
Here's a paper on it, if your interested: http://www.svgopen.org/2011/papers/72-Integrated_Power_Analy...