I'm just thinking about CM6 and standard Google apps. Is there any way to put a link on the SD card linking to the EMMC so that programs could access the internal memory but think they're accessing the SD card? I'd imagine if it was this simple someone would have thought of it already but figured it was worth asking. Another thought occurred. What about changing the directory the memories mount to, perhaps with a software switch so you could make emmc mount to /sdcard? Just a thought.