Does anyone know if the Wii's SD slot can interface with SDIO devices? There are SDIO to RS-232/USB bridge devices in the wild; I wonder if they could be used with the Wii....
According to Wikipedia all SD-compliant slots can interface with SDIO devices, as they are electrically identical. So, the question becomes, how much ASM is necessary to interface with an SDIO bridge from the Wii? I'm sure it's harder than the EXI bus. If an SDIO-enabled code handler can fit in 32KiB, it will work with almost any Wii game by reserving itself the top 32KiB of RAM prior to running the apploader.
Of course, Wi-Fi is also an option. The fact that MegaIOS hasn't seen a public release suggests to me that Wi-Fi debugging is much harder than EXI debugging. (I'm sure megazig could speak to this aspect better than I could.)
@CosmoCortney, I'm pretty sure the Wii's front SD slot doesn't use the EXI bus, and is entirely different from the SD Gecko in terms of circuitry. So while it should be possible to use it for transferring data (e.g. with SDIO), it won't be the same circuitry / logic that the USB Gecko uses.