NPR broke the somewhat surprising story that a vacancy on the Supreme Court will come this year, and the more surprising, perhaps, news that the vacancy will not be the result of either Justive Stevens or Justice Ginsburg retiring.
Speculation of a replacement has of course already begun:
Possible nominees who have been mentioned as being on a theoretical short list include Elena Kagan, the current solicitor general who represents the government before the Supreme Court; Sonia Sotomayor, a Hispanic judge on the U.S. Court of Appeals for the Second Circuit; and Diane Wood, a federal judge in Chicago who taught at the University of Chicago at the same time future President Barack Obama was teaching constitutional law there.
[UPDATE: At SCOTUSblog, Tom Goldstein has a nice post outlining Souter's legacy to date. He reminds that one of the most important majority opinions Souter authored, of his 156 so far, was the 5-4 decision in McCreary County v. ACLU, a Ten Commandments case that outlawed the government monument. Goldstein notes that this ruling in in a precarious position going forward.]