LGBT families will be, by definition, different, and need their own solutions to many things. One is the possibility of co-parenting.
Co-parenting, i.e. a gay male couple and a lesbian couple teaming up to raise a family, is currently an uncommon but growing choice for LGBT families. One benefit is the presence of role models of both genders, thereby countering the claims of the religious right that such children are disadvantaged. Yet having four parents is definitely outside tradition, and seems difficult.
Co-parenting with four parents at once sounds difficult. But it may also be arranged as a combination of 2+2, with each child either predominantly under the care of the gay couple or the lesbian couple. For example, in a co-parenting arrangement with four children, the gay couple can take care of two and the lesbian couple can take care of two. The other couple will act as extended family.
Increasing co-parenting also has an LGBT-wide effect. Co-parenting helps integrate more gay male couples, who will mostly not have biological children in the foreseeable future, into the family framework. It encourages the LGBT community to become more family friendly over time. Therefore every family values orientated LGBT ally should support it.