Just opened mine an hour ago. Version 3.0 Sonic Stage in the box. They really want you to use their Atrac compression. In Sonic Stage, Import your files (or let it create your libray), then it will convert as needed.
I am now listening to music. Meanwhile I have downloaded Sonic Stage 4.3 from Sony website, as well as the 4.3 security patch.
However, they have an MP3 driver that will allow you to load MP3 onto this device, without Sonic Stage (you'll need to install). Doesn't say if it will allow WMA too.
I'll be trying more tomorrow.