Exact sentiments from DTB here. The market bubble is not being created by higher demand due to more people, etc. It is being created because lenders are widening theri spectrum of "qualified" buyers. And even the legitimately qualified are being over-extended by gimmick lending programs. As DTB pointed out, once these ARMs start coming to a head and the owners are possibly looking at a 9% loan (pulling a number out of the air but it's been MUCH higher), then they are gonig to be immediately house poor and unable to stay in that house. I really think in the next 2-4 years, there is going to be HUGE opportunities in the middle to upper-middle class demographic of homes available on the cheap.
Areas such as Mjolnir referred to are probably much less susceptible due to the affluency and churn of people coming in and out of certain areas (usually advancing metro areas). Also areas that simply don't have room to expand (i.e. NYC) there will always be a rise in price cue to simple supply and demand.
I debated selling our house in the past 6 months to sit on the sideline in a rental property for the next few years. We have about 35% equity built up in our home in just a year, so we could sit on that cash or buy a smaller house to hold as an investment property later. But we decided to sit tight because we really like the area that we live in, and our house works well with me working from home and my wife staying at home with our son.
These, of course, are just my opinion and it is based on the 7-8 RE investing books that I have read. I am, by far, not a person that needs to be listened to. I just like to talk.
