This doe not mean that same sex couple will be able to petition for permanent residency for their partners yet and won't be able to do so unlike the Defense of Marriage Act (DOMA) is overturned but it will have an impact on many families. The new policy will allow immigration officials so that they may consider LGBT immigrants’ families for purposes of exercising prosecutorial discretion in deportation proceedings. This may provide immigration protection and relief for some LGBT immigrants and their families, and prevent immigration officials from unnecessarily tearing apart bi-national same-sex couples.
Lamda Legal has created a helpful FAQ sheet on the subject.