Too many empty units, not just single family homes, but rental apartments too. Calculated Risk did a good job of examining the numbers and showing charts, so I'm referring you to his commentary.
The outlook for housing depends on an important lesson: that we cannot look at the single-family home market in isolation. Every politician, journalist, and blogger who is trying to promote a clever solution misses the point: if you make the owner-occupied market better, you do so at the expense of the rental market. And then rental houses go up for sale, rental condos go up for sale, traditional apartment buildings get converted to condos, and the newly-finished condos do not get rented out but instead are offered for sale. The only solution is population growth, which will take some time.