This is almost exactly what I had thought up for myself a few weeks ago and have been spending hours trying to make one at home - and today find someone is making it!
Basically a neoprene DSLR cover with lens operational and clear plastic back to to enable OVF viewing as well as see LCD and controls.Then put on a lens cover and you'll have a WR cover system at fraction of WR DSLR and lens cost. Not perfect access to all controls but you can fire the shutter and push buttons, and if you're patient, maybe twiddle a thumbwheel. IMHO this is much better design than 99% of the useless gimmicks out there at the moment.
This is what M4/3 needs until somebody finally makes some WR bodies and lenses.