I want to know how to extract the vertices of any KML polygon and also calculate the co-ordinates of such vertices in Degree Decimal format. I am looking at a batch process.
Can we use QGIS Sextante to do such a thing?
This should be no problem using Sextante (now just called "Processing" in the newest versions) in QGIS.
I would first use the "Extract Nodes" tool, followed by the "Add Geometry Columns" tool. If you need to convert the coordinate system first, you should also be able to do that via ogr2ogr, which you can use in Sextante as well.
You can create a 'model' using these tools, and run it in batch mode by right-clicking on it.