The best thing for Justine would have been if Sharapova made the final. Then Justine would have won easily, and it would have made headlines.
If she beats Ivanovic, no headlines in the US.
No, Maria proved at the US Open Final she is probably actually tougher mentally than Henin. Slam Finals so often do come down to who wants it more/who is prepared to go for it more and so forth...
*I am not being completely naive here though, I know what you are getting at. She pretty much sucks on clay and seems to fit right into Henin's game.
But I, personally, think that Justine got the better draw in the form of Ivanovic. Justine does get nervous quite often, especially in Slam Finals, and she has so much more experience than Ivanovic who is going to be extremely nervous herself. Justine has both the edge of play AND the edge of mentality over Ivanovic.
Ana isn't exactly a great mover on any surface, especially clay, and Justine can exploit that too.
In terms of play, Justine has proved against Serena and Janko that she can pretty much take anyone apart on clay. It seems that the only way you are going to stop her is by mentally beating her. Sharapova has the potential to do that, Ivanovic absolutely does not...
Ana is a better draw for her. Expect a comfortable, yet edgy, 6-4 6-1 claycourt lesson.