Joannie finished 16th in the SP at 2007 Worlds to go with her 5th in the FS. Nakano was 7th in the SP and 6th in the FS and finished 6th to Rochette's 10th.
Nakano did not skate at the Olympics (Miki was sent instead, and bombed). She went to 2006 Worlds instead of Miki and placed 5th to Rochette's 7th.
Rochette's two gold medals were one at Skate Canada 2006 and one at TEB 2004. In 2006, she had a gold and a 4th place, and in 2004 she had the gold and a 5th place, and in that season she won bronze in the GPF. She has never won medals in both her GP events, and she won no medals at all in the 2005-2006 GP season.
Nakano had a gold medal and a 5th place in the 2005 GP, and she won bronze in the GPF. Last season, she won silver and bronze in her two GP events.
Oh, and Nakano has a silver 4CC medal to Rochette's bronze.
I don't see that Rochette has any edge over Nakano, who is a far more consistent skater. The one and only advantage that Rochette has at Skate Canada is home ice.