According to OnTheBaseline, the No. 1 ranking is up for grabs at Wimbledon. Serena Williams could theoretically be dethroned by No. 3, Jelena Jankovic, by her sister, Venus Williams ranked No. 2, by Caroline Wozniacki ranked No. 4, or even by Samantha Stosur ranked No. 6. Elena Dementieva is currently ranked No. 5, but is not playing Wimbledon due to an injury.
With Serena being the defending champion, she has all her points to defend. Stay tuned to Wimbledon 2010. It could get interesting!