That's not what was said. The question that was asked was whether the state of Virginia had to follow the law as written, using unconstitutionality as the base argument against enforcement. In answering the question, the judge said that Virginia does not have to follow/enforce the law because the law is unconstitutional.
Other states will have to ask the same question for themselves. Eventually, I expect that the ruling will be extended throughout the country by a supreme court ruling.
In summary, the judge answered the question that was asked, but answered in a way that easily lends itself to extension beyond Virginia.
That’s not true. I think that commentators were stressing that this ruling only applies to the case brought by VA and that the other cases were still pending. If Obamacare is unconstitutional it is unconstitutional, period.