Just released? ATRAC is the technology that's been behind compressing music onto MiniDiscs for the past 10 years. The format can also be used on Sony's Network Walkmans (and of course the CD players you mentioned).
My mistake. As a layman I guess I just noticed their recent huge push in advertising Atrac3 technology. It probably started as a response to Apple's "x,000 Songs In Your Pocket" slogan.
But I stand by what I said before about Sony getting into the market. No amount of infighting can ignore the fact that Apple is ripping it up with their iPods. They'll hafta do something soon, or simply forget that market segment alltogether.
Think about it, for Sony to get involved just makes sense given their history. For Sony, the walkman was what put them on the map for music lovers everywhere. Apple is basically replacing them in that respect.