Is there an SVG Map library like Google Charts?

In the meantime, google released Geochart Maps, an update to the geomap. It creates SVG maps, and you can make them whatever size you want, with aspect ratio or not. I developed a plugin to build maps using this API for wordpress. Check it out at http://cmoreira.net/interactive-world-maps-demo/

With the Wikipedia SVG Maps you can "shade" countries by simply using CSS.

Some examples of using such maps (SVG, CSS, HTML, JS) can be found here. That will export either a full map, or just the stylesheet which can be applied to a local copy of the map. I'd recommend using Opera for the best viewing experience, but it should work in all the browsers that support SVG.

Wikipedia has a lot of SVG Maps, but it is not a library.