Sony Ericsson also announced today a second Walkman mobile phone, the W600a (W600).

The Sony Ericsson W600 features a 1.3MP digital camera, 176 x 220 pixel TFT display, 2 stereo speakers, RDS FM Radio, MP3 and AAC music player, 256MB internal memory, 3.5mm stereo headset jack, USB and Bluetooth.
The new Walkman W600 is a Triple-band 850/1800/1900 MHz phone. The W600 is apparently not extensible with more memory. I guess Sony is positioning this Walkman phone in the lower price-range.
More details on the Sony Ericsson W600 product page and in this press-release.

Engadget attended the Sony press-event and are excited about the screen of the W600. They also have a life shot of the W600.

The first Sony Ericsson Walkman phone is the W800, which was introduced earlier this year.