Because of the excess of children in the foster system, and the fact that the supreme court ruled that keeping same-sex couples from adopting was unconstitutional, it's unlikely that these cases will hold up in smaller courts now. There are too many reasons why same-sex couples should be able to adopt, and not enough reasons why they shouldn't.
Being homosexual, gay, etc. has been shunned for many years for not being "natural" or "normal" by societal standards so it's not surprising to see that even despite their huge victory in the U.S, having marriage rights they still have challenges to face. Being able to adopt children is one of these challenges, this victory over E.L. shows that same-sex couples have a fighting chance for their right to be able to adopt children and this will be used as a catalyst for what the future can bring.
The adoption judgement made in the case of VL vs EL will certainly have a large affect on future cases. Of especial note is the recognition that the state has misapplied its own law - the fact that the Supreme court reversed the decision could imply an advantage for same-sex couples in future.
Arguing for a particular case does not validate the general case. The public policy danger of generalizing from the particular (saying that this one case X should now be precedent for allowing all same-sex couples to adopt) is that society could then make a general law regarding such adoptions, with the law-makers feeling perfectly justified in doing so because of case X.