It's a very important ruling, especially as it's unanimous and builds on previous rulings in similar cases (notably Austria).
The Court concluded that 'de facto marital cohabitation' must include same sex couples under the right to private life and freedom from discrimination.
I find para 92 (near the end) to be particularly important in terms of the Court's own understanding of its own jurisprudence:
92. Sexual orientation is a concept covered by Article 14. Furthermore, when the distinction in question operates in this intimate and vulnerable sphere of an individual's private life, particularly weighty reasons need to be advanced before the Court to justify the measure complained of. Where a difference of treatment is based on sex or sexual orientation the margin of appreciation afforded to the State is narrow and in such situations the principle of proportionality does not merely require that the measure chosen is in general suited for realising the aim sought but it must also be shown that it was necessary in the circumstances. Indeed, if the reasons advanced for a difference in treatment were based solely on the applicant's sexual orientation, this would amount to discrimination under the Convention (see E.B., cited above, §§ 91 and 93; S.L., cited above, § 37, ECHR 2003-I; Smith and Grady, cited above, §§ 89 and 94; and Karner, cited above, §§ 37 and 41).
At the same time ILGA-Europe reports of latest developments of the Schalk and Kopf case on same sex marriage where Prof Robert Wintmute has been given intervener status in front of the European Court of Human Rights (arguments regarding admissibility at this stage).
There is a very interesting link to the oral arguments here.