Starting to lose the will here...
In theory, apparently you can mount a network drive and access the files on it. In practice, however;
- I can't
- Even if I could, you appear to have to manage playlists manually via another app, you don't get the nice front row interface
So I would be inclined to use the most useful piece of functionality - enabling a USB drive as the primary storage - whack a terabyte drive in the back, and use @TV as intended, by syncing your whole library via iTunes.
DVD playback works now, once I realised you only copy the VIDEO_TS directory, not the AUDIO_TS one as well. But it's in black and white on my proper telly since I can't get composite to work (I can feel a trip to John Lewis coming on). I did this by copying files onto the box itself, rather than streaming (see above, and I'd be wary of streaming video anyway) - I can't confirm without having tried the USB drive hack yet whether these end up on the @TV drive or the external one. The faff involved is making me consider whether or not to convert those movies I want on the box to DivX (?) and manage them via iTunes as well, since it's only to give the kids films to watch without them trashing the (owned) disc.
The web browsers (the built in one's called Couch Surfer I think and the Firefox I added later) appear to work but are currently next to useless as I have no keyboard and mouse attached. I haven't yet attempted to use my iPod Touch and remotetap or suchlike to control it, though I may after I've spent some time with it.
So in summary: not sure the atvflash thingie is worth $50, bearing in mind:
- I can't get some of the key stuff to work
- In practice, some of that key stuff (eg streaming from network drive) would be impractical day-to-day
- the ability to add applications (in particular Spotify nnnggghhh) appears limited
- all of these hacks are available free if you can be bothered to find them and can be bothered to work out how to install them (non-trivial from cursory investigation)
This is all based on just a few hours of play though, I'll keep it (there's a 15-day money back guarantee on atvflash) and work with it to see if I can coax it into a manageable solution. If I can get the external USB drive working, then I'll do precisely what I suggest further up, and just use it as it was intended, but with a drive in the back to provide monster storage (and wait for Apple to provide that update themselves, at which point I'd revert to original firmware I think).