Here's the deal. You can't write Wii games, because the media identifier code on the media (hardcoded) cannot be altered. In other words, you can't make a DVD-R, +R, -RW etc look like a standard pressed DVD.
Also, reading a Wii game requires a low-level reading process. Otherwise the built-in hardware on the DVD drive repairs the "bad sectors" on the disc - thus the copy is not a 1-to-1 copy of the original. There are only a couple of DVD drives that can low-level read a disc in this fashion (several Hitachi LG brand drives). This is mostly due to a mistake made by the manufacturer that left a "security hole" open and has been exploited by programs such as RawDump (often later firmware version corrected this mistake - thus its very important to ensure the firmware version of one of these drives before buying).
