I think Venus has the slight edge. Serena has been pushed by people she'd normally win in 2 quick sets. Venus needs to improve her consistency to pull of the victory though.
However, I don't think either of them can get pass maria. Maria has been playing really well in her first 2 matches. She's very focused and is hitting the ball well. Maria is probably the favourite to repeat at the moment.
-MARTINA HINGIS-Unconditional Love & Support, Always and Forever, Genius, Legend, StarAll the Best, Elena Dementieva, Anna Chakvetadze, Ana Ivanovic, Jelena Jankovic, Zheng Jie, Vera ZvonarevaKeep Fighting, Keep Believing
Novak "Nole" Djokovic