Try using assimp (regrettable name). Blender format is on the wish list. Add your voice to the wish list. I think this library should used for convertion, using a library/DLL like Python does. A potentially good library will receive the attention of Blender users and help it gain traction. Then only the Blender format need be maintained internally. Any coders originally participating/coding format interoperability for Blender internal could move their skills over to the assimp project and this project would field conversion issues/bugs. This could apply to networking and a number of other libraries available in the wild that could be used to replace fuctionality in Blender. GEGL for non-destructive image transforms among other things, springs to mind.