OK, first of all, the majors are about equal. Henin-Hardenne managed to win three of the four biggest matches of her life, which ain't bad. In fact I bet Justine herself probably preferred to win Roland Garros.
I can definitely see her in another final, especially as Serena and Venus are still not as dominant as they were in 2003. Justine gained a lot of power especially on her serve between her last Wimbledon and her illness, so I would give her a good shot to either win or at least make another Wimbledon final.