Sneak attack on marriage: Are the rulings by two Ninth Circuit Judges appropriate?

At the National Review Bench Memos Blog, Matthew J. Franck raises various questions about the propiety of the recent rulings by Ninth Circuit judges Alex Kozinski and Stephen Reinhardt interpreting the Federal DOMA. Franck asks: 

Are these orders of Judges Kozinski and Reinhardt not then “advisory opinions” on the meaning and constitutionality of federal law, of just the sort that the courts have held since the 1790s to be inappropriate for judges to pronounce?

Related: 

Two 9th Circuit Judges grant same-sex “spousal” benefits, one rules Federal DOMA is unconstitutional