So, it's happened. By at least one metric, for at least this very moment—it could change tomorrow—Apple is now bigger than Microsoft. Apple's market cap passed Microsoft's today, just two months after edging under Walmart. The latest showing from Google Finance puts Apple's market cap at $225.98 billion to Microsoft's $225.32 billion.
Reflecting briefly on where Apple and Microsoft were ten years ago, and snapping back to the present, it's kind of a quietly epic moment. [Google Finance]
Update: Dylan Tweney points out this chart of the last 10 years of Apple vs. Microsoft.