Obama's pick to replace retiring Supreme Court Justice John Paul Stevens is, as expected, Solicitor General Elena Kagan. The New York Times and Washington Post already have (generally positive) coverage of the nominee on their sites, including biographies, notable writings and a glimpse of potential nomination issues.
In a break from precedent, Kagan has never been a judge (having withdrawn her name after a lengthy stall by Republicans). Her notable achievements have been as a White House advisor, Harvard Law School dean and present role as solicitor general. She should be considered a "stealth" candidate, as she has produced scant and inconsequential writings by which to determine her jurisprudence.
But, of course, there will be plenty of red meat for the confirmation hearings.