I don't know if the real estate bubble is done popping. I suspect it is not.

If there is another shoe waiting to drop on the U.S. economy, its commercial real estate. Bloomberg reports that $165 billion in commercial real estate loans mature this year. They must be refinanced or sold. Either way, it seems like some losses must be taken.

As of July 8, 2009, $108 billion worth of properties were in default, foreclosure or bankruptcy. That's a lot. Throw in the 22-year high of vacant apartments, and you get a picture where landlords are really struggling.

Goldman Sachs took $700 million in losses from commercial real estate in the last quarter. And it did so without a hiccup. And we have the various government bailout programs to thank for that. Without the government sponsored ability to earn their way out of this mess, that $700 million could've been a much bigger deal.

The one hope regarding commercial real estate is that the problem is pretty well known. And so far, it's not moving the stock market.

Bloomberg threw out some big numbers for regional commercial real estate debt that was due in June. $463 million worth of office loans in Houston, $986 million in industrial mortgages in Portland, Oregon, $96 million in retail property in Orlando.

Was this debt paid? Was it refinanced? Is it in default? We don't yet know. And we won't know for up to 90 days, which is a typical grace period. It will be a while before we know whether these loans will become losses.