Right now EFI boot-loaders and the EFI boot stub in the Linux kernel carry the same initialization code to setup an EFI machine for booting the kernel. However, with this EFI handover protocol support, this redundant code could be eliminated. Intel and others want to have the initialization and booting of the kernel just within the kernel's EFI boot stuff than also copied within the boot-loader.
The Linux 3.6 kernel provides the handover protocol support on the kernel side but the EFI boot-loaders need to be update to support the EFI handover protocol entry point. When they do have this support, the responsibilty of EFI boot-loaders come down to just loading the kernel image from the boot media and providing any user-interface for boot menu options (e.g. selecting different kernels).
This support was merged into the kernel for Linux 3.6 with this merge window pull. Additional EFI handover protocol information can be found from the kernel.org patchwork.