Checkm8: What you need to know to keep your iPhone safe
cfenollosa.com
cfenollosa.com
If anything this should be a boon to users. It allows them fully to use their devices they own. Honestly, it is inexcusable that apple makes users have to hack their own devices. You should have the option similar to enabling or disabling secure boot on your PC.
As to the market for stolen iDevices. It still exists, but generally involves parting it out. Like sell the screen, cameras, and battery ect... Honestly, while unfortunate that things get lost or stolen. I don't see how this really changes anything.
The only big question right now is whether the exploit allows an override of the iCloud lock, therefore opening again a market for stolen iPhones.
I'm sure somebody here will be much smarter security-wise than me, so please send me contributions or corrections if there happens to be any mistake!