Nielsen crunched Q4 numbers today, and the results will likely have Apple analysts jumping up and down. The findings, focused on those who've purchased a smartphone within the previous three months, indicate a huge spike -- from 25 percent in October to 45 percent in December -- in iPhone purchases since October as an obvious result of the launch of the 4S. Conversely, the number of recent Android buyers fell by 14 percent in the same period. Of course, these numbers are directly affected by Apple's latest product launch and by no means should be any indicator that Apple is poised to win the battle against its bitter rival, as iOS continues to trail Android by over 16 percent in market share. Looking at the war for the third spot, RIM's US market share declined by 2.9 percent from Q3 to Q4, falling to 14.9 percent -- not a surprise, since it only captured the hearts of six percent of recent buyers this quarter -- and Windows Phone slightly increased from 1.2 to 1.3 percent. Full press release and chart can be found after the break.