Stacy Keibler may not be the only top WWE Diva leaving the company in the summer. Trish Stratus could very well be unassociated with WWE by September.

There was a reason for Trish Stratus making a surprise return on the 6/26 edition of RAW, only to do a 2:00 clean job to Mickie James. As it turns out, her WWE contract is expiring sometime in August. WWE doesn't know what her long-term plans are. She is currently negotiating a new contract with Johnny Ace.

Also, Trish Stratus is marrying her long-time boyfriend in September. At the very least, she will most definitely be taking some time off in September.
source: Wrestling Observer Newsletter