The problem with Lena is that you could predict what is gonna happend- you could see it in her eyes that she is struggeling. if she want to stay in the highest ranking, belong to the top players and not go back to the 10's level when she stood in previous years, she'll have to be killer like finish games with power atittude. I guess that players like S. Williams, Davenport, Mauresmo and Sharapova wouldn't lose this kind of advantage (4-0 30- 0) because their rivals realize that their are superior and that they have no chance in that point of the game. in contrast, lena is a great fighter but psychologically she steel does'nt have this killer instinct that will scare other players (like schnyder).
here we back to the Serve issue- its not statistically crucial (sometimes it is...), but psychologically this weakness is very important to her image as killer player, not only from the rival point of view but mainly from lena point of view. when she serve the game she does'nt look comfortable and sometimes you feel that she would preffer that her rival will serve all the time.
What i'm saying that by improving her serve, she will be much stronger, not only statistically , but more important psychologically. her rival will understand that lena is in another league. for me, this is the most important lesson from this tournament- if she wants to stay or even go forward in the ranking this year.