I think "Canadian Heritage" should be the next theme of the notes. The notes should retain the potraits on the front, and on the back, there will be a series of Canadian Heritage throughout the ages. The $5 shall feature Canadian Heritage from hundreds of years ago, depicting the First Nations, then progressively working up to the $100, showing the "new" Canadian heritage, where multiculturalism is the new face of Canada.
Just a thought.
I think the next series MUST be polymer.