I'm sure that Michele is right; hiring of freelance / continent / temporary workers is on the increase, because they're generally cheaper (lower salary, fewer or no benefits) and because they're less trouble to add to and even less to remove from an organization's workforce.

As of 2009, total nonfarm employment in the US. was 130.9 million, while self-employed but not incorporated came to 9.8 million. (Self-employed but incorporated were counted as "employed.") No doubt some of the self-employed are also among the employed (e.g., someone working full or part time for an organization and also working independently or as a contractor).

Perhaps more depressing are the Census Bureau's figures for average household income, adjusted for inflation:

2009: $49,777
1999: $52,587
1989: $48,463