Wow this seriously blows, if it is in fact the case. Though it's quite possible that the chip is simply a little controller as the plug is probably tapping into the usb connection so I'm guessing it needs to send digital info. As there aren't enough pins to simply use the remote as 3 independent switches (on top of the mic). So it probably isn't really a DRM device, it's just that it needs to be encoded a special way for the iPod to understand it as otherwise the tip of the plug would need like 6 or 7 rings and monstrous cable on top of additional chips in the iPod. As it probably has nothing to do with the management of digital music files, but could have some kind of encryption or ID that manages witch switch can be used with the iPod. Mind you, I would be very pissed, albeit not surprised if apple did in fact charge 3rd party companies to know how to tap into this. Or if there is some kind of identification required to get into it, that apple would sell.
Most probably, there is no identification, just that apple will sell the way to talk to talk to the iPod instead of giving it for free, than a company or some random dude will find it and spill the beans.
Well just have to wait and see.