Apple’s iPod and iTunes Store remain the dominant MP3 player and online music store, respectively, in the teen market, according to the results of Piper Jaffray’s latest bi-annual Teen Survey. Of the 92% of students that said they currently own a digital media player, 86% said they have an iPod, up from 84% in the prior survey. While the percentage of students saying they are planning on buying an MP3 player in the next 12 months dropped…