No, a 5 will count as a pass for the league tables, a 4 will count as a pass for funding requirements for 6th form, but only for the first couple of years, at which point a 5 will count as a pass for both the league tables and sixth form funding requirements.
What employers decide will count is up to them. If they are only interested in candidates with a specific level of numeracy, then they would count a C grade and a 4 as acceptable. If they want to hold younger candidates to higher standards than older candidates, then they would accept a C or a 5.
Confusingly, for the first year of the new GCSE, the grade 5 boundary will be set by numerical interpolation between grades 4 and 7, whose boundaries will be set by the proportion of students who get a grade C or above and a grade A or above this year. In future years this will be aligned to some nebulous international standard, and the grade boundaries for a 4 and a 7 will be set by using a national reference test sampling the performance of a random group of Y11s the year they sit the GCSE. Therefore it's unclear how the grade '5' and the notion of a pass or fail will actually represent any sort of consistent standard.
What is fairly clear is that the 'pass rate' as referred to by the league tables will drop by an estimated 23% in 2017, thus for practical reasons people who recruit mainly from this cohort will either accept the government notion of a 'pass' as a 5 and severely restrict their candidate pool, or set their own acceptable standard, aligned to the previous 'pass' standard which is a 4.
What's absolutely clear is that people like Bolognese will not understand the nuance and simply say '5 is a pass' and students in the first cohorts to sit these exams will be severely disadvantaged in future years.