During their Q3, 2009 conference call today, Apple chief operating officer Tim Cook revealed that Apple forecast "traditional" iPod sales would begin to decline (sales of iPod shuffle, iPod nano, and iPod classic), which is why they developed the iPod touch and iPhone.
Apple maintained an over 70% US share of the MP3 market, and sold 10.2 million iPods, including iPod touch and the aforementioned traditional iPods. Though they once again didn't break down the sales mix, traditional iPods were down year over year, while iPod touch sales continue to grow, up 130%. Add to that 5.2 million iPhone sales last quarter, and it looks like Apple's new focus on their new mobile platform is well founded.
As Apple has always maintained, if someone is going to cannibalize their market, it's going to be Apple themselves.