What would be the difference between coffee and corn?
None, for the purposes of this thread's examples.
Why do you think the virtual futures would be priced anywhere near their real world counterpart?
I have no idea what a virtual future is.
But if you wanted to trade corn contracts, bitcoin is an excellent notary service for such contracts.
Bitcoins and anything like it cannot be backed by something real. If it could, it would have been done.
Everyone who purchases a real-world good with bitcoins, or fulfills a contract with bitcoins, begs to differ.
With cryptographically-signed digital certificates, you have as much flexibility as you need, to describe anything in the world.
Corporate entities can certainly back digital certificates if it is in their interest to do so. If I was rich and wanted to back bitcoins with gold, there is no reason why I cannot do that.