Hi Michael,
As of right now, the GeoChart will not seamlessly work with the current version of gadash. The problem lies in that the Analytics API outputs the locations of countries in a different format than the input for a GeoChart. This is something the team is working on doing in future development.
Although the library has the ability to use any chart type that Google Chart Tools supports, it may not work without some sort of extra code. One feature we wanted to focus on was making the library robust in that you have full control over the output of the analytics data. That being said, you can use the custom callback function to get the output of countries from the Analytics API and write your own piece of code to integrate it with the GeoChart.
Hope that helps :)
- Shan
UC Irvine Student, contributor to GAdash