Soon after Microsoft launched the new Zune players on November 13, the hard drive-based Zune 80 was sold out online and in retail stores around the country. While the 80GB unit was indeed well received, there's another reason behind the shortage: Microsoft decided to prioritize the manufacturing of the flash-based Zune 4 and Zune 8.

Microsoft's decision to focus their efforts on the two flash-based players was based on the company's forecasts and early retail orders. These devices compete in the most lucrative part of the MP3 player market, which is widely dominated by the iPod nano. Fortunately for Zune fans, Microsoft says it has stepped up production and significant Zune inventory will begin hitting stores within the next 7-10 days.