I agree with a lot of the comments posted here: there are a number of DAP's being offered to the market that meet or exceed the iPod in features, and are fast approaching the ipod in terms of build quality, form factor & styling, but IMO they are simply not going to knock the iPod king off of the mountaintop until they at least TRY to formulate some sort of US national marketing strategy, much less an international marketing strategy.
That's not to say that all it takes is a sound marketing plan, & the DADA mp3 sneakers will become the market leader, lol. Good, consistent marketing goes hand-in-hand with exceptional quality of product, no matter what consumer product you're talking about. If you make a lame, poor-quality product but run a nation-wide ad & TV campaign for it, you'll get some attention initially for the product, but with that attention comes the realization that it was all hype, & the product becomes a one-hit wonder, or a "flash in the pan".
On the other side of the coin, as we see quite often in the DAP market, if you actually offer a quality product that is feature-rich & has great form-factor, but the only "advertising" that prospective buyers see of it are the occasional vague spec-sheet disclosures prior to product release, or the random blog-site postings, and the market demographic is (for the most part) just going to fall back into line with what they know the most about, & what they are most comfortable with: the iPod.
The marketing of the product, IMO, is more key than a lot of the competitors seem to realize.....