Hi,
This is a quick reminder for Inkscape developers that OpenRaster project has been evolving [1] thanks to Cyrille Berger of Krita team and Øyvind Kolås of GEGL/GIMP teams for quite a while now. The project was mentioned in this list early in March this year. I've just checked again and it turned out that it wasn't really much discussed.
Here is a short overview. OpenRaster aims to become an OpenDocument format (ODR) for multilayered raster graphics with clipping paths, masks, layer effects etc.. It is going to become a standard for exchanging of project data between users of different applications. Repesentatives of several opensource projects have expressed their interest in supporting this file format by providing either exporting or importing (or both) filters for it, when this standard is approved by respective OASIS TC as such (or even earlier). Krita/SVN and GEGL/CVS HEAD already have initial supporting code. There is a draft document from June 2006 available [2] to read.
In case of Inkscape this task might be quite simple, since it can already write OpenDocument Draw documents, and exporting an Inkscape SVG document to ODR, when ODR is ready, would be a matter of exporting each layer to a respective PNG file and combining them into ODR layers, with clipping paths or masks where applicable (some effects like Gaussian blur could be exported to an effect layer, too, possibly by means of XSLT), then saving it to a ZIP archive (sure, I oversimplify this description :)).
If any of Inkscape developers is interested in supporting this file format in the future (especially since it is going to have basic vector graphics capabilities) -- at least exporting to it, the team would appreciate your input. Most discussions are held in CREATE mailing list [3].
[1] http://pippin.gimp.org/OpenRaster [2] http://create.freedesktop.org/specs/OpenRaster-draft.pdf [3] http://lists.freedesktop.org/mailman/listinfo/create
Alexandre