AFAIK put ext2 and rootfs to NAND is posible too and easy to do but the real problem is linux kernel for TP2 is not yet implemented to access that memory, NAND, only kernel and initrd are placed on NAND and it will be put to RAM when the phone is booted then no access anymore to NAND
Another way is some guru can write a bootloader for it to control the way to select what address to load kernel and OS like grub bootloader did on PC. BTW we will have really native Android and everything on TP2, eg. multiple OS on mobile such as WM & Android together and can select to boot. But this way is really hard caused by the bootloader and WM OS is closed source and we must RE it to understand how it work and modify it to do such things!