Is Windows Phone catching on? Nielsen reports that Windows Mobile stands at 9% of installed base in the US.
In the last report, WP7 took 1%. This time around, Nielsen did not provide data for WP7. But WMPowerUser blog optimistically suggests that Nielsen folded WP7 data into the Windows Mobile data as one and that WP7 has increased so much that it is able to off-set loss of older Windows Mobile devices.
That is possible. Until we get clarification from Nielsen, we won't know with any certainty. We do know that there are the "other" section with 1".