Since new coding is pretty much ramped down for SQL Developer , I needed a place to test out some features in a way that everyone can benifit. I've created a project on sourceforge, http://sourceforge.net/projects/esdev. The current extension there enables support for readonly XMLTypes and adds export to excel in native excel inthe worksheet thanks to Poi.
I hope this project also shows how easy it is to extend base functionality. The web cvs isn't working yet but once it is, take a look and see what it took to add this.