Housing market hit bottom?

The lead story in today's New York Times talks about recent signs that the housing market has bottomed out in most metropolitan areas in the country. The notable exceptions are Phoenix and Vegas—the places where the expansion in housing ba-boomed in the past decade. An optimistic point of view from the story:
For the first time since early 2007, a composite index of 20 major cities was virtually flat, instead of down. “We’ve found the bottom,” said Mark Fleming, chief economist for First American CoreLogic, a data firm. The release of the surprisingly strong Case-Shiller Price Index, compiled by Standard & Poor’s, followed earlier reports that sales of existing homes rose last month for the third consecutive time, while sales of new homes rose in June by the largest percentage in eight years.
And a word from the not-so-optimistic:
All of these improvements are tentative, and come after a relentless decline that knocked more than half the value off houses in the worst-hit cities. Some skeptics say they believe the market is merely pausing before it resumes falling and that much of the life in the market is coming from speculators. Even the most enthusiastic analysts acknowledge that rising unemployment, another leap in foreclosures or a significant jump in interest rates could snuff out progress.
Here's a link to a cool interactive graphic that gives details about housing prices in different cities. And here's the link to the story itself.