I'm not convinced about the editorialized "may spell the death". It just means that if Facebook wants their Like buttons to be used by companies serving the EU,

I'm not convinced about the editorialized "may spell the death". It just means that if Facebook wants their Like buttons to be used by companies serving the EU, they will need to take steps that those companies are confident that they obey the law. Assuming that Facebook benefit from the arrangement, why wouldn't they do this?