Vash on the WorldWind forums has put out a plug-in for Geoserver so that it can serve out DDS images. This will help speed up WWJava as it converts downloaded tiles to DDS before display, serving as a DDS skips that step.
Download the plug-in: plugin-dds-geoserver.jar
To use it just copy the plugin-dds-geoserver.jar and worldwind.jar from the WWJ sdk into the subdirectory "webapps\geoserver\WEB-INF\lib" of your geoserver installation and restart geoserver.