Senior analyst Gene Munster of research firm Piper Jaffray is predicting 16.5 million iPod sales for Apple's holiday quarter after analyzing three months of NPD data. The Cupertino-based company is holding a conference call today after the market closes to discuss its financial performance for its December quarter, where Munster also expects to see a slight upside to Wall Street's consensus of $0.78 on $6.42 billion. "Our analysis of iPod unit data from NPD for all three months of the December quarter leads us to expect iPod shipments around 16.5 million; previously, when we had only two months of data, we had been expecting a range of 15.5 million to 16.0 million for the December 2006 quarter," said Munster. The analyst notes that the expectation of 16.5 million iPod units is based on various assumptions, and reminds investors that iPod average selling prices will be down in the December 2006 quarter vs. previous quarters due to a higher ratio of iPod shuffle sales to other iPod models, which could total a 10 percent drop in the average iPod selling price quarter over quarter.