Defenders of the new health care law think Justice Clarence Thomas should recuse himself from the Court's consideration of its constitutionality because Thomas's wife has been a leading critic and paid lobbyist against it. Critics of the law think Justice Kagan should recuse herself because as Solicitor-General she may have participated in meetings about how to defend law, and because she expressed support for the law in emails during her tenure. In an end of the year State of the Judiciary report focusing on judicial ethics, Chief Justice Roberts told Congress to mind its own business and have faith in the Justices' recusal decisions:
I have complete confidence in the capability of my colleagues to determine when recusal is warranted. They are jurists of exceptional integrity and experience whose character and fitness have been examined through a rigorous appointment and confirmation process. I know that they each give careful consideration to any recusal questions that arise in the course of their judicial duties. We are all deeply committed to the common interest in preserving the Court’s vital role as an impartial tribunal governed by the rule of law.
Here's the report (PDF). And here's the NYT story on it. For a statement that both sides of the issue can probably rally around, it's hard to beat this from the report:
Judges need and welcome guidance on their ethical responsibilities, and sources such as the Judicial Conference’s Code of Conduct provide invaluable assistance. But at the end of the day, no compilation of ethical rules can guarantee integrity.