Well, the folks at Apple beg to differ....
http://docs.info.apple.com/article.html?artnum=93548.
It specifically lists a whole set of Creative products, including the MuVo, that are compatible with iTunes.
Though I am having the exact same problem, where I can't get it to recognize the device.
I had the one I got from Audible, but never used, and wanted to set it up for my kid.
Not sure if perhaps the Audible player was set up by default for PC use...not sure.
Will look through the threads more.
-kathy