Not really.
In the 06-07 and 07-08 seasons, no one would argue that Asada and Rochette were rivals in any sense of the word other than the literal (aka, two competitors at the same events). Asada was in another league, Rochette was still struggling with consistency issues (she is now, admittedly). It's not really a question.
The question, as posed by the initial poster, has Rochette BECOME a rival for Asada? In the two seasons, she's beaten her more times than not (TEB 2008, 4CC 2009, Worlds 2009, Japan Open 2009 vs GPF 2008, WTT 2009, Olympics 2010), and their scores are often very close to each others. Now, whether you believe this is because Asada's skills have deteriorated (no 3-3 combination, too much focus on 3A), Rochette's have improved (consistency, jumps, PCS), both or neither is up in the air, of course.
That said, I sorta feel that a rivalry needs an off the ice component for it to be a memorable one: Plushenko-Yagudin, Asada-Kim, etc. This certainly doesn't.
This I agree. I think most of their fans are comfortable enough for them to skate in the same shows, and also both skaters have been quite friendly to each other. In one article, Joannie even said that she thinks Mao is the most graceful skater now. There's a lack of tension that the other two rivalries have.