I like the looks of that Logitech Wireless DJ system. The $64 question in my mind is does it need any helper or "server" application running on a host PC to function, or can it play from a NAS or similar "non-PC" repository of music files? I can't tell from the limited info on their website.
I used to use a Rio SonicBlue for relaying stored music from a PC to the media room sound system. It worked well (not wireless, though, just ethernet connection) but requires the installation of a server app on the PC, and that the PC always be on.
Now we've upgraded to an Audiotron, which is more flexible, although still not wireless. Its best feature is that is happily streams from a dumb 1TB NAS sitting in the media closet, so we don't need any PC anywhere in the house booted to play music. It biggest drawback is that the remote is simple (no display) so to get song/artist info, you have to read off the panel display. And you have to build playlists elsewhere, like with Winamp or Audiostation on a PC. You can use a laptop or pocket PC to give full function remote control including building a playlist on the fly.
I would be a little concerned about interference to or from cordless phones or home WiFi access points because the Logitech operates in the 2.4GHz band too. I'll presume by careful choice of channels on the phone and WiFi AP that all 3 could coexist.
The price is VERY attractive; I'll look forward to some user reports here.