I am currently playing with OpenSceneGraph. In order to create a pipeline for creating animated models and then loading them into openscene graph without having to do any hard work like installing the autodesk FBX SDK or compile the collada importer I want to be able to export directly from blender with animations to an .osg file and then load this file into open scene graph. The only version of the osgexport for blender I could find (http://hg.plopbyte.net/osgexport) has not been updated for the latest version of blender (2.57) - so I have updated the exporter and you can get it from here:
(I have also sent this as a patch to the author of the osgexport script - Cedric Pinson).
Update - this script needs a bit more work - I found a few more api issues when I tested different models. I'm removing the link for now and will post a new one when I have fixed the problems I am seeing.