I have read that Netgear ReadyNAS devices support streaming media to TiVoHD, for example the RDN2000. From the product description:
all ReadyNAS units feature the ability to stream content through DLNA® compatible devices like game consoles and televisions or even TiVo
As I understand it the ReadyNAS devices emulates the TiVo Desktop (Plus) software, TiVoHD does not support DLNA.

Someone on the TiVo Community Forum has reported getting it working.

Can anyone confirm whether or not this works with Au/NZ TiVoHD?