According to the rumors section of MMAWeekly.com, it appears there could be some changes to the WEC's next card on May 12.
The original main event was lightweight champion "Razor" Rob McCullough vs. Rich Crunkilton for the title. The new listed main event on MMAWeekly.com is Crunkilton vs. UFC fighter Jamie Varner (Varner is also scheduled to face Jorge Gurgel at UFC 72 in June, but that could be scrapped).
Also, MMAWeekly.com lists Jason "Mayhem" Miller vs. Hiromitsu Miura for the May 12 WEC card. While the WEC has not confirmed the addition of Miller to their roster, the Wrestling Observer also reported that Miller will be fighting for the WEC 5/12.
Miller is without question one of the top fighters in the world not fighting in a major organization right now. He's fought once in the UFC, losing to Georges St. Pierre. In addition to being an exciting fighter, Miller is charismatic and has the potential to be a huge star. He already has a large cult following, but he has what it takes to become big time with the mainstream.