What exactly *is* the conflict between the GPL and the App Store T&Cs, anyway? The FSF have a piece up that talks about the "only install app on five devices limit" but I think that's a red herring -- AFAIK you can only sync iTunes DRM content (i.e. movies and music) on five computers, but iOS apps can be installed on limitless devices attached to an iTunes account. And the company who ported VLC, Applidium, were hosting a full download of the VLC app source on their own site. I can't really see the difference between this and, say, a Netgear router firmware where the company hosts a download for the source; in both that case and the VLC app, the user gets a binary file, and can optionally grab the source and compile the binary themselves and run it (in an emulator, admittedly, in the case of the iOS app, but you're still running it. Pretty sure the GPL distribution clause doesn't have to target the exact same platform, does it?)

What am I missing, if anything? What exactly is it that blocks GPL on the App Store?

I bet that is the case, yes. I do know that if your BT phone line defaults to not sending caller line ID, you need to tell the Sky box the call prefix to make it come back on for the dial out call -- the entire system is literally tied to the caller ID and nothing else. If you have Multiroom it's strictly non-negoitable, you must have a phone line, it must be plugged in, it must send caller ID.

I also strongly suspect this is why they still use a built-in modem and not the Ethernet port. It'd clearly be preferable in this day and age to just wireless hook the Sky box to your free wireless Sky router, but they couldn't then guarantee the two Multiroom cards were at the same address. It'd be too easy for me to sell you my second card and use some manner of IP tunnel to ensure that when your box connects out, it does so from my address. Sky are none the wiser, except they've just lost half their rental revenue.

To be fair to MS, they have had a research group publishing in this area since around 2001 http://research.microsoft.com/mesh/