An interesting look at what might just be Apple’s most profitable product, the third-generation iPod Shuffle, reveals some interesting data. Research firm iSuppli observes that even with packaging and headphone costs included, a present iPod Shuffle only runs While the iPod Shuffle’s launch comes at a period in time where MP3/PMP market is congested with competition and the economy is in upheaval, iSuppli predicts a mere 5.4% decline in device shipments during 2009, but expects things to rebound as soon as next year with a mild 2% growth.