Will never happen, Microsoft hasn't made the same mistake with their cryptography as Sony.
The person responsible for the KK/ JTAG hack, TMBInc is anti piracy. No one has yet to figure out how he got the 1BL key, he has said no interest in hacking it further.
No one with the necessary skills wants what you want. Because the JTAG hack was abused and people used it to host modded lobbies and cheat, it did a lot of harm to the XBOX and Live. There's a whole forum built around this, se7ensins. After now what's happened to the PS3, as an online console it's finished. All the cheaters and modders will all jump ship to the PS3, PSN will be full of 9 year olds running modded games and aimbots etc.
Presumably the discovery of the flaw in the cryptography was aided by the PS3 JB which have allowed hackers to learn a lot more about the inner workings of the console. The JTAG hack has been around in it's previous form since 2007, and they have much more access to the XBOX than the JB allowed on the PS3. So if it was going to happen it would have by now.
The JTAG hack is perfect. They have full access to the console and hypervisor, you can pretty much do what you want with the console. The JTAG hack was patched by Microsoft before it was even released; as the hack was announced on the day it was patched it's suspected that TMBinc gave MS knowledge of the hack before it was released. There are enough JTAG consoles around for those who want them, but not enough for it to go mainsteam. So Microsoft doesn't go out of their way to block them from playing the lastest games etc, they seem content that they've patched the JTAG exploit. Instead they are far more concerned with DVD backups.
