There's a file attached to this OP. Download it and unpack it somewhere that you can get to it easily with command prompt (I'm too lazy to make a batch file as this is a giant headache since I trusted others on this and it's burning me in the end. My fault for not testing this myself and trusting other people..).
open your command prompt and navigate to wherever you unpacked the folder to.
run the following commands in this order
moto-fastboot flash mbm allow-mbmloader-flashing-mbm.bin
moto-fastboot reboot-bootloader
moto-fastboot flash mbmloader mbmloader_hs.bin
moto-fastboot flash mbm mbm.bin
moto-fastboot reboot-bootloader
moto-fastboot flash cdt.bin cdt.bin_16G
All of these commands should go through successfully.
Hit the power button to turn the phone off.
Hold both vol keys on the side of your phone and press the power button to boot into the boot selection screen.
Select Normal Boot
Press Vol +
If you haven't jacked anything up too badly the phone should boot back into the ICS leak (.84) so you can at least use your phone. I'll look into a further fix later. I'm at work.
The phone will not charge any more while powered down until we find a better fix so be aware of your battery and manually power it down if you drop extremely low so that you have some juice to boot it back up and charge. Don't let it run down completely.
Update: If you get stuck on the fastboot-failed menu every time you plug your phone in when it's powered down, I found a fix. It just needs a successful flash of the first 5 steps. It should reset the failed flag. Once you're done with the first 5 steps, rather than flash the cdt file again just execute command moto-fastboot reboot. Without the period obviously. The phone should reboot normally into your .84 leak without hiccuping and requiring you to use the BP menu to boot the phone. This also re-enables charging with the phone off. This doesn't fix any other issues. Just those that are able to get back up and running on .84 but were having to go through the menu every reboot.