Right now all our placemarks are the big pins with yellow circles. Many KML styles now have much more sleek markers. We should pick a better default one (maybe a small geoserver logo? That's probably a bit much), but also allow people to easily customize theirs.
One nice way to do this would be to use the point symbolization of SLD, at least the 'external graphics' (as the well known ones might be a bit more challenging? - would have to write them out to a file and point the KML at them).
Note also that GE comes with a lot of default placemarks, we may try to figure out a way to leverage those as well, let users pick those for their SLDs if they're in google earth.
Improvement
Closed
Major
Icons for KML placemarks should pick up point SLD stylings
Looked into if the spec supports "vendor parameters", so that we could come up with something "kml specific" and associate a placemark icon with any rule. However i cant really find anything in the spec or the schema. The closest thing that i can see is the idea of CssParameters.