Scrolling through my e-mails, I found some info that was new to me. The guys from Fraunhofer IGD are trying to unite their efforts to store data in special container formats for easier transmission and compositing in a new implementation called the Shape Resource Container (SRC). Nice namegiving btw. This shall contain all the implementions of ImageGeometry, BinaryGeometry and PopGeometry they already developed. You can find more info (including commands for using aopt for conversion) on this page. Highly recommended for everyone working with X3DOM.
Edit: Seems like there is competition concerning container formats for 3D web applications, BLAST from the XML3D people server a similiar purpose. Details can be found here.