There's a new Khronos project glTF which wants to establish a standardized run-time file format for 3D assets: http://www.khronos.org/gltf, geometry is stored in binary blobs so they can be dumped directly into buffer objects, and the scene description is in JSON for simple (and somewhat fast) parsing. Unlike FBX or COLLADA this is meant as an "engine file format", not as asset exchange format between 3D packages.
glTF seems nice. We are currently adding export support for glTF it to our tool - http://clara.io. glTF is very similar to the run-time format used by both http://Verold.com and http://Sketchfab.com but it is standardized.
glTF is basd on Collada pretty closely I understand.
