GRUB Gurus, I realize the answer to my question ultimately may be determined by the Intel and AMD architectures. Is it possible to boot alternately to a 32bit OS and a 64bit OS with GRUB 2 and a 64 bit processor?
http://en.wikipedia.org/wiki/GNU_GRUB mostly refers to Grub legacy and http://www.gnu.org/software/grub/grub-faq.html states "The current release is working on Intel/AMD PCs, OpenFirmware-based PowerPC machines (PowerMac and Pegasos), EFI-based PC (IntelMac) and coreboot (formerly, LinuxBIOS), and is being ported to UltraSparc." without reference to processor width.
I also checked "https://help.ubuntu.com/community/Grub2" but found no reference to CPU width.