This lot have developed the software I've been waiting for... playing the audio and video media from the home PC on the PS2.
Currently only for the US, and only in pre-release. But soon... (from the FAQ)
We intend to have versions for all regional PS2's.
At the moment we do not support any USB Ethernet devices. We currently only support the Sony Ethernet adapter. We will be looking into expanding this in the near future.
And from the forum:
QCast currently only supports .mp3 audio tracks [for DivX], but we will support AC3 tracks soon