The biggest confusion that I had when getting this to work is that you can only manipulate the UEFI boot loader when booted in UEFI mode. Since my existing Debian installation, as well as the installer CD booted in BIOS emulation mode, I failed to set up the boot loader at first. Key is the efi shell, which I can conveniently access on my ASUS motherboard by hitting Exit in the EZ mode to get to the Advanced mode, then hitting Exit again.
Update: For proper kernel configuration, see [https://www.kernel.org/doc/Documentation/x86/x86_64/uefi.txt] . Starting with 3.7 I had no kernel output any more without these settings.