Let’s assume that the current justices are exempt from any new term limits law and that they, like Justice Sandra Day O'Connor, will serve until around age 75. Given the health issues of half the current court, and the increasing pressure to retire when a like-minded president sits in the Oval Office, we believe that's fair.
Seventh Circuit Judge Diane Wood spoke to a Duke Law School podcast last week and to Reuters earlier today, both times saying she was interested term limits proposals, though she didn't go so far as to endorse one over another.
A lot of this comes down to how you'd handle the tenures of the current nine.