It's possible. According to Stephanie Myles, here are the WTA #1 scenarios:
- If Serena gets to the final she's #1
- Sveta and Boots have to win it all and Serena would have to lose before the round of 16
- Dina has to reach the final, Serena has to lose before the quarterfinal, and Boots can't win it. She can also get to #1 by winning the whole shebang and Serena doesn't make the final.