This was uploaded from Pebble's GitHub page (https://github.com/pebble/pebble-3d) and was accompanied by this message:

pebble-3d
Here's the moment you've all been waiting for: the release of Pebble's 3D drawings. Looking forward to seeing some awesome designs on thingiverse!

PDF and Step files are included

FILES ARE FOR REFERENCE ONLY. SUBJECT TO CHANGE WITHOUT NOTICE.

All Rights Reserved. 2013 Pebble Technology Corporation.

Check out - http://getpebble.com/

I'm a big fan of Pebble and as a backer, I'm really looking forward for them to begin shipping.

If Pebble decides to put this up on their own thingiverse page (hint hint) or asks me to take it down, I'd be more than happy to comply.