This is a pretty big deal. You don't have to be a $1M net worth individual if you self-incorporate.
The federal securities laws define the term accredited investor in Rule 501 of Regulation D as:
1. a bank, insurance company, registered investment company, business development company, or small business investment company;
The use of proper traditional exchanges sets the stage for short selling and derivatives, which will be a big part of Bitcoin's coming-of-age.
(Although SecondMarket isn't
exactly a "proper traditional exchange", it's a hell of a lot closer than we're used to)
I believe in the USA that an SBIC is an investment firm that invests in small businesses. This would be different from just any incorporated company.