We can only speculate, but we can express a high level of confidence in saying that it will be Chief Justice Roberts along with Justices Kennedy, Ginsburg, Bryer, Sotomayor and Kagan. Justice Alito, who has said he would not attend future SOTU’s after last years attack on the Court by President Obama, is in Hawaii for a speech to the state’s bar association. We wish we were there as well; it’s sure to be a much more comfortable place from which to watch a speech in the middle of winter. Justice Thomas has expressed concerns that the speech is a highly partisan event and rarely attends and Justice Scalia also typically sits it out.
Scalia has gone so far as to call the event “… a juvenile spectacle”. I’m not sure how that fits into his doctrine of originalism, given that this “juvenile spectacle” is a constitutionally mandated function of the office.