I suppose this is the marquee matchup of the day. An in-form-like-we-haven't-seen-her-in-years Serena vs. an emotionally and physically exhausted Baby Beluga, who is still the hottest player coming into the tournament (I mean performance-wise). I don't know what Tracy Austin is smoking when she says she gives the slight edge to Serena. I don't see what weapons Dinara has that can hurt ReRe. She doesn't move as well as Serena, she doesn't hit the ball as hard, and she doesn't serve the ball as hard or accurately. Sure, Dinara beat her in Berlin, but on clay all of Serena's power is mitigated. On these hard courts, which everyone is saying plays faster than the grass at Wimbledon, there's no way Dinara can hang with her. Dinara's only chance is if Serena has a let down after her high quality and emotional win over Venus on Wednesday night. If Serena is not in top form, Dinara has a shot. Otherwise, this one will be over in two fairly easy sets.
So from two of the better servers on the tour to two women whose serves have been the biggest knock on their careers (well, and mental stability). But at the end of the day it will be the serve that is the difference between these two well-matched ladies, as Lena seems to have finally gotten that thing under control. She has served as well as I have ever seen her serve at this tournament. That should allow her to hold her games much easier than Jelena will.
As for JJ she has had yet another "huh? She made it to the semi's again? I didn't even know she was playing" tournaments. All credit to her. I didn't think she'd make it this far. But I think is, once again, the end of the road. Elena moves extremely well and hits flat, powerful groundstrokes on both sides. JJ's only chance here is if Elena chokes. I don't see that happening though because (a) as opposed to JJ Elena has actually won a Slam semifinal before and (b) theirs is the first match in the afternoon (1:30) so there will be less attention on their match, which benefits the headcasier Elena D.
So bottom line: If all four players play at their top level, expect Serena and Lena to win. But if Serena and Lena come in cold or iffy, JJ and Dinara have a very real chance to make the final. Incidentally, if JJ and Dinara make the final, regardless of the outcome JJ will regain her #1 ranking.