The idea has been played with, but a foundation which does this needs a whole lot of money up.front (establish secure infrastructure, badger manufacturers, …)
Apparenty M$ doesn't even do the infrastructure part itself; that's been outsourced to Verisign. A sensible move, if you ask me, but it doesn't necessarily save money.
Anyway, AFAIK no corporation has been forthcoming with the $$ necessary to do this. Unless that happens, we can talk about doing a Foundation (or using an existing one for this purpose) all day long, but won't accomplish anything.