I think that software is a unique industry in that it is a "self growing" industry. Unlike other industries, in which the more workers there are, the lower the pay, I think with software developers the opposite is true. I believe that the more software developers there are, the more things will be automated, and therefore the demand for software will grow with the supply.

Furthermore, since it the complexity of software grows exponentially rather than linearly, I believe that as the number of software developers grows linearly, the demand will grow exponentially ;).