Last time I read the story (unless i read it wrong) the eFuse was in the TI OMAP processor and not Android OS itself. That would make it hardware based and not software based which makes it a lot more hard to get around.
From the arcticle:
http://www.mobilecrunch.com/2010/07/...try-to-mod-it/
"It requires a hardware fix, apparently, only available through Motorola, of course. This is the equivalent of a MacBook detonating some core component if you try to install an OS to dual boot."
So this is why older Moto devices like the first Droid dont have this issue