This tool, once implemented, will allow the bootloader to be bypassed and a custom kernel to be executed. According to Dan, this is similar to kexec "in that it works around a locked bootloader, but this approach is much more flexible and robust."
Before you get too excited, though, it's worth noting that this is a developer-only tool. It's designed for ROM and recovery devs and is not a utility made for the average Joe. In other words, don't expect to just download Loki and flash it through ADB or some other method.
With this being said, this is for Galaxy S4 phones only on att or verizon, but since this was done wouldnt it make sense to port it or whatever they do so it can work on the xperia phones with unlock-able bootloaders ? Rather than fighting to get our "TL" bootloaders unlock this would be an awesome workaround