Basic Geo charts are already there, but not documented so far.

In future we are going to support all type of visualizations from Grammar of Graphic, so it includes spider chart as well. In fact it is Polar Parallel chart and it will be possible to create it when support of polar coordinates will be added.

Given that you called them facets, I'm going to assume you're familiar with ggplot2. In retrospect, I thinking adding non-Cartesian coordinate systems was a mistake. They are a huge amount of work and only make a handful of charts easier (and most of which, like the radar chart, are not that useful).