According to a posting on the US Supreme Court's website, the Court has scheduled a conference for this Friday, January 15, to discuss Mumia's case. Specifically, they are looking at the Philadelphia DA's request to have Mumia executed without a new sentencing hearing.
The Supreme Court has apparently been waiting for the ruling on the Spisak case, which was also released yesterday. In Spisak, the court ruled to reinstate Spisak's death sentence, but it is still unclear what impact this ruling will have. The common thread between Mumia and Spisak is the "Mills" precedent, and the Court yesterday ruled that Spisak's case did not meet the standards of Mills.
This is the link to the Supreme Court posting:
Here is a recent article by Jeff Mackler, explaining the importance of the Spisak case: