Who controls Solidcoin's special millionaire accounts?
RealSolid controls those accounts. He claims that he has selected several trusted people to operate them, but we have no way to know if this is true or not.

There also seems to be a somewhat fundamental flaw in the reasoning. If we trust people because they have the most to lose, why should we trust people who have unspendable coins? Unspendable coins don't reflect having anything to lose at all.

It should also be pointed out that those with more than a million coins have complete control over the transactions included in the chain and who gets all of the mining rewards. They have merely to announce blocks in pairs -- everyone who doesn't control a million coins can be completely locked out by those who do.

Also, I think "the poor can trust the rich because they have the most to lose" fails the giggle test. (That is, you can't say it with a straight face, so it's probably not even close to true.)