It would make sense that the Wii would have a separate section of flash/EEPROM memory of some sort reserved just for the OS and nothing else. To bad the Wii doesn't have detailed specs. It would be interesting to know how much space is reserved for the OS. It could be the same physical memory as the 512MB - as in it may really be 1GB of internal memory, but the OS is written such that 512MB is reserved for the OS an 512MB is reserved for user data. Kinda like having two partitions on one hard drive.