Also, keep in mind that when the older spouse converts all or part of their RRSP into a RRIF they are allowed to use the younger spouse's age to determine the minimum annual RRIF withdrawal. 

http://www.cra-arc.gc.ca/E/pub/tg/t4040/t4040-16e.pdf

See page 26.  I believe you must opt for this at the time the RRIF is created, and that it cannot be done after.