NPR: Justice Souter is retiring. Obama gets to pick a Supreme Court Justice.

Via NPR (which probably means Nina Tottenberg who really does know all things Supreme Court):

NPR has learned that Supreme Court Justice David Souter is planning to retire at the end of the court's current term.

The court has completed hearing oral arguments for the year and will be issuing rulings and opinions until the end of June.

Souter apparently won't leave the Court til his replacement is confirmed.

UPDATE: Pete Williams from NBC has the same news.