We're looking at just over 6 months of sales and the iPhone is rocking the marketshare in the Smartphone category like you wouldn't believe. According to Canalys (whose numbers we've admittedly doubted before, but these results look pretty solid), the iPhone has reached 28% marketshare among Smartphones in the US and 7% worldwide. That puts it at #2 in the US and #3 worldwide. They're even ahead of Motorola.
Also, the iPhone is beating the pants off of the PalmOS (down to 9%) and also Windows Mobile (21%) in the United States. The only question left is whether or not Apple can gain on RIM's imposing 41% share. That will require converting a lot of business users.
Actually, the other question is whether or not Apple can maintain that share without releasing a 3G iPhone in the near future. The drumbeat of analyst, stockholder, and most importantly consumer desire for the 3G iPhone is going to get steadily louder in the coming months.