I have no trouble at all in believing that there is a real estate bubble in places like L.A., Las Vegas, and different places along the east coast, but I'd say that most areas of the country, i.e. "fly-over country"

there isn't much of a distiguishable real estate bubble at all. For example, would you say that there is a bubble in Texas where in some areas, like Austin and Beaumont, real estate prices have actually been going DOWN? In other areas, such as Colorado, appreciation has been very minimal, basically just keeping up with inflation.
While I understand that from a macro perspective, we have several potential problems looming in front of us such as a potential currency crisis, run-away inflation, or a stock market crash, I'd say that in "normal America" the potential macro problems pose a much greater threat than a busting real estate bubble that never seems to have happened. (Houses in these areas still sit on the market for 90 days or more).
Also, fundamentally, it isn't hard to recognize the problem that L.A. is about to have when they run out of people who can qualify to buy a $500,000 house, or when people end up making much larger house payments when their ARMs end up putting them on much higher interest rates. These problems don't loom nearly so large in Nebraska, although I wouldn't argue that too many people are way too overextended in credit-card and mortgage debt.
--Ben