Features overall just strike me as half-assed. The wifi functionality is lackluster. The codec set still lacks other far-more-common-around-the-web video formats. The sound quality will undoubtedly be decent, but the Touch isn't hugely worse for people who don't engage in EQ juggling. The memory expansion also isn't as versatile as the year-plus-old Cowon D2, which in terms of core functionality is not exactly hugely inferior to the Zen either. At the other end of the spectrum that the Zen represents, the Sony NWZ-A8xx or 7xx are much more focused music / light video players which perform very well.
I'm sure that there are many people who will go for it, but to me it's a bit of a shotgun approach to the featureset. Given the competition I wanted it to be better thought out than it has turned out to be.