Just to add my 2 cents to the discussion. I recently purchased a Slim Devices Squeezebox. I had previously ripped all my CDs to 192K for my 3g iPod but after a lot of investigation, I decided to rerip every to flac (about 300G and counting). I run it out he coax digital into my 990. All I can say is WOW. I love it. Great device.

So I decided to do a little experiment. I now had all the songs in 3 formats, MP3, flac, and CD (some I also have the LP but that another story). I played the MP3 through the squeezebox, and A/B through the 990 the CD version, also digital coax in from my Marantz CD67SE. I could easily hear a difference, especially the soundstage and depth, but also the MP3 just sounded compressed in the dynamics. Then I compared the flac through the squeezebox to the CD. No difference that I could hear on any music format.

The gist of this is, for me at any rate, mp3 are fine for my iPod and headphones (senhiesers px100), but for the main system the flacs are great and you can't beat the convenience.

BTW I am hardwired ethernet, I am not using the wireless portion of the squeezebox.
I think devices like this (they also have an audiophile version called transporter for $2Gs!) [edit: sorry gonk I just saw you already mentioned this] are only going to get better, aa will the lossless codecs. Makes things likes jitter almost a non issue.

Now to back up all that music.....