The Mississippi Supreme Court granted Cory Maye a new trial today (PDF), though on different grounds than the Mississippi Court of Appeals, which granted the trial based on a change of venue issue. The state's supreme court instead ruled that Maye's trial judge should have let the jury consider a "defense of others" defense, and that the judge's refusal to include that in the jury instructions amounted to reversible error. The court also said that Maye's new trial can take place in Jefferson Davis County, which is what Maye wanted, and is where the incident took place.
As I understand it, this decision means Maye is virtually guaranteed a new trial next year unless there's plea agreement between his attorneys and the state.
My 2006 Reason feature on Maye here. And here's Reason.tv's documentary about Maye's case: