2009 Uso = 2003 Uso
Weather prediction says rain during the day on Friday. This is like USO 2003, when the semifinal matches that were scheduled for the day were delayed to Friday evening.
There are many more similarities: In 2003, two Belgians were in the SF on the opposite sides of the draw. First up, Kim Clijsters played an American multiple slam winner, Lindsay Davenport, and beat her in straight sets. In the second match, another Belgian, Justine Henin, played uberpusher Jennifer Capriati which turned out to be one of the all-time classics. Henin won, then beat Clijsters next day in the first all-Belgian US Open final.
On to 2009, the first SF we will see is Kim Clijsters playing an American multiple slam winner, Serena Williams. The second match is the "less popular" Belgian, Yanina Wickmayer, playing uberpusher Caroline Wozniacki.
Both Lindsay Davenport and Serena Williams are not pushers but are "attackers". Both Henin and Wickmayer are Belgians whose mother died young.
Conclusion: Yanina Wickmayer for the win.