In theory, having your music play throughout your entire house would be a great thing to be able to do. It's convenient, right? But honestly, how often are you wandering throughout your house for long enough that you need multiple speakers playing the same thing to keep up continuity? And it's not like your whole family will want to listen to the same thing at once. To me, while it sounds cool at first, it's a solution to a non-existent problem.
Apparently Eos disagrees with me. Its new wireless iPod speaker system cradles your precious music player in the central dock then broadcasts its music to up to four wireless speaker satellites. The "convenience" of this system don't run cheap: $299 for the dock and $129 for each satellite. You'd better really not want to pause your music when you go get something from the bedroom for this to be worthwhile. The whole system will be available next March.