LOKI is a tool for use by Rom developers. It won't really help you to mod your device. In fact it will be used by developers to bypass the bootloader all together which will allow for things like custom recovery, custom roms, and custom kernels. This is similar to what we had with other devices in Kexec. According to Dan Loki is different in its approach than Kexec and is much more robust.
LOKI is great, and it is better than nothing, we are still hoping to see this thing fully unlocked! If that doesn't happen Loki will serve our modding purposes. You can also look into purchasing a developer edition which was also announced today.
Via XDA