Porn browsing mode ftw, but still, I don't think it's as secure as you're being lead to believe.
Besides, with a laptop you're up a river regardless. Without an EFI password, the thief that has your laptop will install a fresh copy of OS X on it before it has a chance to be found. With an EFI password, it is still very easy to get rid of the password and reinstall the OS. Easy. Piece of cake.
This would be great for helping an owner locate their LOST mac, but it sounds too complicated and a bit too misleading to actually be helpful. Ideally, the Mac would ping out and try to beam up its location when you wake it.