Not happening. It would likely cost from tens or hundreds of billions at the very least to colonize the Moon (remember Mitt Romney trashing Gingrich in the debates). A project like colonizing Mars in this lifetime will have massive costs probably ranging in the trillions and would most certainly take a government to fund.
It will take over a decade to transport thousands of workers there, whilst also accounting for transporting years of resources so that the thousands of workers can survive while building the colony. Imagine building New York city from scratch on a planet 20-30 years away. Finally if the planet is habitable, it will likely take decades for a region to develop ecologically such that anyone wants to bother living there.
After all this effort, then you have to find a way to transport millions of civilians all this distance. In addition, you had better damned hope there are either fossil fuels on Mars or we've perfected the utilization of solar energy, otherwise people will have to live with medieval-age tier technology.
Unless there happens to be a gigantic shit-load of useful resources lying around on Mars, there's no reason to bother colonizing it rather than figuring out a way to reduce the population on earth leaving more resources and space per person.
The Asteroid mining project on the other hand, sounds fucking neat-o.