>Do you think it's possible for a routine to be added to sedna that will cause 32 bit output to be converted 64 bit output for processing on the newer processing chips?

More important would be to switch over to 64 bit in maximum no. records, file offsets and so on. And this could happen on any 32-bit compiler as well, but might require parts to be rewritten, probably new header formats defined (only readable on new versions), changes in locking code and so on.