Nielsen’s December survey of the U.S. mobile phone market:

According to the latest research from Nielsen, the high-profile launch of Apple’s iPhone 4S in the Fall had an enormous impact on the proportion of smartphone owners who chose an Apple iPhone. Among recent acquirers, meaning those who said they got a new device within the past three months, 44.5 percent of those surveyed in December said they chose an iPhone, compared to just 25.1 percent in October.

This should help drive the numbers for next week’s Apple Earnings Announcement through the roof.