The Idea was first discussed and proposed here in March 2014, the draft standard has now been produced for comment and further discussion. It's available for download from the 3D Printing Association and Youmagine.

Originally discussed here - http://richrap.blogspot.co.uk/2014/03/universal-3d-printing-filament-spool.html

Overview video here -

comment, feedback and if you decide to adopt the standard, do talk about it and let me know.

Update and release of the standard (Issue 1) - http://richrap.blogspot.co.uk/2014/11/update-on-3d-printing-filament-spool.html

The 3D printing association is supporting this standard, so also feel free to talk to them about it and please get involved if you can - http://www.the3dprintingassociation.com/