Bankruptcy is a federal proceeding and same-sex marriage is not recognized on a federal level (yet).  Therefore, same-sex spouses cannot file joint bankruptcy petitions.

One significant drawback to this is that the cost of two bankruptcy cases will obviously be higher than for one case.  However,  same-sex spouses tend to have less joint debt than heterosexual couples.  Therefore, if only one spouse has debt problems, it might be more advantageous for just that one spouse with the debt to file bankruptcy.