USB turntables are already available from several other companies like Ion, Audio Technica or Numarc. Sony enters this niche market a little late, but I guess there is still demand.
The Sony PS-LX300USB comes with bundled software that can record your LPs directly on CD-R or CD-RW, MP3 format and ATRAC format.
The Sony PS-LX300USB USB turntable will start shipping in Japan on April 15th for 28,350 yen (~$275). Now word yet, if Sony is going to release this gadget outside of Japan. Via this Sony press-release (Japanese).