GLBSE effectively becomes the underwriter, broker, and agent for a number of "securities", some for legalish enterprises and some...whatever. He changes rules, creates application fees, and criteria for inclusion on the exchange.
This is anecdotical, but I don't think GLBSE ever acted as the underwriter of any security (they would have had to buy [usually at a discount] all the yet-unsold shares after an IPO, which they didn't).