Do you see what I'm getting at? The entire value of these things (minus the raw brass, silver, or gold) is dependent on 1) Mike being honest, and 2) you never being able to verify if mike was honest with the coin you're holding. He sells an object that requires you to risk throwing away everything you paid for it just to be certain you can trust him.
Only problem is his honesty has been verified by the random sampling of physical bitcoins that have been opened and redeemed by presumably independent persons.
1 BTC coins 46/3836 = 1%
10 BTC coins 0/11 = 0%
25 BTC coins 6/249 = 2%
100 BTC coins 12/34 35%
http://www.uberbills.com/casascius/I think we can be fairly certain that all coins that have been sold have been loaded with the BTC. If he were to load all BTC as expected, but keep a copy of the private key *that* is where a problem might be.