It's true, I did find the linkbait. Whatever the charts mean, the iPhone is selling well in North America. Whether or not it's beating Windows Mobile (which it appears to be) or behind the BlackBerry (which it appears to be), the relevant bit is this: it's a close race, it's anyone's game, and the iPhone is doing spectacularly given the amount of time it has been available.
If you'd like to talk about the numbers, I'll recommend this thread over at WMExperts, where the community is actively defending and disputing the numbers. The iPhone is the purple one in the charts. If you'd prefer to comment that this is a nice looking graph or that there is enough purple on the chart to satisfy you or that you just like purple, you can comment here.