Arduino Due
The RTC is compatible (when using latest library). Accessing the SD card is possible with the addition of some jumper wires, but difficult due to the fact that the shield obscures the ICSP header where these wires must be connected.
Add jumper wire from pin 11 on shield to ICSP pin 4.
Add jumper wire from pin 12 to ICSP pin 1.
Add jumper wire from pin 13 to ICSP pin 3.
Use the standard SD library (not the Adafruit fork). Do NOT #define SOFTWARE_SPI or MEGA_SOFT_SPI in the library.
I've got pins 11-13 mapped, but after looking at the schematic, could someone confirm that there won't be a problem with the i2c or any of the other pins being pulled up to 5v.
I've got a level shifter, should I run pins 10-13 through it? What about SDA and SCL.