We all build choropleth maps, they're a staple in editorial. To automate this process, our team began a simple CSV-driven mapper application that allows for easy definition of map stylers based on columns of data. The tool uses D3 to render world or US-state maps, and allows for color to be applied at thresholds or on a linear heat scale. The tool includes preliminary export options for PNG and SVG, and lays some groundwork for an interactive experience.
This tool is only a proof of concept at this stage, but we've made open-source to promote community involvement. Enjoy, and happy mapping.