I heard an ad on the radio the other day from a mortgage broker. They offer to pay your PMI if you get a loan through them.
The problem is not the 3% down. It's the fact of giving a loan to people who only have 3% down. They are generally not the best credit risks.
Not to mention the nosebleed prices people are paying for even crappy stocks. It is getting harder and harder to buy anything at value prices.
How about the profusion of novel methods of funding? And the crazy housing prices in some places like San Francisco? There must be some kind of bubble somewhere. Auto loans, student loans not getting paid. Hard to see how it can all end well, but it's not over yet: yield curve still curved.