The "grid-parity" (same price of utility electricity and solar electricity) was a long shot a few years ago, but we are getting closer. How?
The biggest market in the world is Germany, with more than 50% of sold PV. The laws there set a feed-in tariff (a electricity price at which the producer sells the electricity) for 20 years. This tariff is going down every year (means if you install today you get 20years of XX. If you install next year 20 years of XX-5%.
As usuall, market is the driving force. If companies do not achieve this price reduction, they will just not survive. But the technology evolution in modules makes it possible to reach this 5% yearly. How? A mix of better technology and economy of scale. Take a look after September to the proceedings of the European PV Conference and you will see some serious content about that.
For EU countries, system prices of 3$ achieve grid parity. In Hawaii, 4-5$ is already profitable. In California, 3-4$. Those markets with grid parity, if laws are put in place to make it easy to put PV on the roof, will boom with demand; but if the grid is further "protected" from distributed generation, it will take longer.