You think John Paul Stevens will step down

He might.

Pat Leahy is going to put the brakes on anyone to the right of Ginsburg, so there is no way a Roberts or Alito gets through. Most likely, it will be a trial and error type of thing, with at least one nominee getting shot down IMO.

Then again, he's hung on for this long, why bother? He's kinda reminds me of this very old guy I used to work with - he was well past retirement, but kept working. Somebody asked him why he didnt just retire, and he replied, "Because then I'd have to spend all day with my wife." Being a SC justice is a much better gig than moving the lawn, etc.