The W3Schools.com browser stats nicely reflect long-terms trends online; so what specifically can we learn from the graph I made? First, the obvious: Internet Explorer is in a long term decline almost perfectly mirrored by the rise of Firefox. Second, there is something very different about IE7 adoption (plateauing) compared to IE6 adoption (linear) five years ago. Is this partially the WGA effect I predicted? Regardless, its bad news for Microsoft.
Update 2: (July 8) Compare my graph for w3schools.com with this one from oreilly.com: