If you get ushare to start or the Myth UPNP server to start the Netgear will give you access to the content on the server. You can also use the Syabas based boxes (Popcorn Hour, Buffalo, IOData, etc.) and there are several Linux servers that you can run on the core to support them. They work OK and won't break the system (i have tried them).
None of these will give you the functionality of an Orbiter and no access to control. You may also need to do some tweaking to access the DVD images. Possibly you will need to decrypt them to play them.