I use my ZenMicro Photo for virtually all of my music listening. I hook it up to my main system, my car, my wireless headphones, and earbuds. I will be upgrading to Shure or Etymotive earbuds soon.
I liked everything about the Ipod except the fact that it does not support WMA, in which my entire music collection is encoded, and it does not have a replaceable battery.
WMA sounds quite a bit better than MP3 at the same bit rate. A 128k WMA is barely distinguishable from the original and 192k is equal, in my opinion.
It will be interesting to see what B&W is has planned.