It could turn out to be one of the most important changes to the school curriculum and examinations in England since the GCSE replaced O Levels over 20 years ago.
In one of a flurry of announcements since the election, the government announced that it had, at a stroke, lifted the ban on state schools offering the international version of the GCSE, the IGCSE.
In fact, ministers were slightly overstepping the mark. Before the education secretary can approve any qualifications, they must first be accredited by the exams watchdog, Ofqual.
While some IGCSEs have been accredited, others have not. The Education Secretary, Michael Gove, gave the impression of riding roughshod over the regulator in his haste to give the go-ahead to IGCSEs. That might give Ofqual some concern over its future role.
But that aside, this is a significant move. It could herald not only an end to the pre-eminence of the GCSE but also an end to the national curriculum's domination of secondary schools.
To understand the significance of this, it helps to go back to the days of the old O level and its counterpart, the Certificate of Secondary Education (CSE).
The O Level was an exam intended for only the most able 20% of pupils and was the first stage of a university entrance filtering process.
The CSE was introduced in 1965 as an attempt to break the universities' hold on school examinations. It was aimed at the next 40% of the ability range.
As an aside, it is sobering to remember that the remaining 40% were expected to leave compulsory schooling with no academic qualifications - so much for the so-called "golden age" of education.
In theory a Grade 1 CSE was meant to be the equivalent of an O Level pass, but in practice it never carried the same weight and was widely regarded as a second-class qualification.
The creation of the GCSE in 1986, by a Conservative government, replaced both the O Level and the CSE.
It was designed to create a single examination for all pupils, of all abilities, whatever type of school they attended.
Thus the GCSE was the culmination of comprehensive school reorganisation: a common examination for a common school system.
The next big change was the linking of the GCSE to the national curriculum. In effect, GCSEs became the Sats (or national curriculum tests) for 16 year-olds.
So, whereas O levels floated free from the curriculum and followed a university-influenced approach to subjects, GCSEs were inextricably tied to the government-designed curriculum.
That is why, as recently as a few months ago, the last Labour government refused to put all IGCSEs on the Section 96 list, the approved list of qualifications. In effect, if a qualification is not on this list a state school cannot teach it.
The withholding of approval was nothing to do with the quality of these qualifications. Indeed 16 IGCSEs provided by Cambridge International Examinations had already been accredited by Ofqual.
The main reason given for withholding approval was that the IGCSE did not align with the national curriculum (by contrast, the government approved nine subjects which were not core parts of the national curriculum).
The extent to which IGCSEs differ from the national curriculum requirements imposed on GCSEs was apparent in a study produced for the government by the QCA in November 2006.
It found that IGCSEs in English, mathematics, science and French "did not meet the GCSE subject criteria in significant ways". This meant it could not be regarded as a suitable exam for assessing pupils' study of the national curriculum.
For example, in English, the IGCSEs did not always require students to answer questions on prescribed national curriculum texts, such as Shakespeare. Nor did they always require pupils to be assessed on their speaking and listening skills, another national curriculum requirement.
Now, though, Michael Gove has downgraded the importance of the national curriculum by saying state schools can teach the IGCSE.
No one has said that the IGCSE will have to change to match the national curriculum (although that could easily be done). So teachers can now safely ignore the programmes of study, and prescribed texts, without fear that pupils will suffer in their exams.
It is a freedom that independent schools have always had. Now state schools will be free to pick and choose between GCSEs, IGCSEs and any other accredited qualifications.
One school delighted by this is Parkside Community College, a state school in Cambridge. It introduced science IGCSE in 2008, partly because governors - who included academics from Cambridge University - felt it was a better preparation for students going on to study science at A level.
However when the Labour government refused to approve the IGCSE, it had to stop teaching it.
I visited the school this week and joined a class of Year 8s who are now likely to be able to choose IGCSE science next year.
According to science teacher, Hannah Jones, the IGCSE is a better preparation for pupils who want to take the subject at A Level. In particular it involves more mathematical work than the GCSE.
Parkside also likes the fact that the IGCSE, like the O Level, is not split into modules. With all the assessment at the end, more time is left for teaching.
Hannah Jones says that does not mean the IGCSE is right for all her pupils, particularly those not wanting to pursue science to a further level. It will be a case of the right exam for the right pupil.
Executive Principal, Andrew Hutchinson, says the government decision will put his school on a level playing-field with local independent schools, which already offer the IGCSE.
He thought it unfair to have to say to pupils and parents that they would have to move into the private sector if they wanted access to the IGCSE and the advantages it offered to those wanting to pursue the subject at sixth-form college or university.
Parkside had good academic reasons for wanting to be able to teach the IGCSE, which it regards as more demanding for pupils. It is a non-selective school open to all pupils irrespective of ability to pay. It should be able to do what it feels is best for its pupils.
Other state schools will no doubt want to follow. If, like Parkside, they also wish to take advantage of the new government's fast-track to become academies, they will get even more freedom from the national curriculum.
The go-ahead for the IGCSE is a very large nail in the coffin of the national curriculum. It is also the death knell for the principle of a common curriculum and a common exam for all pupils.
In short, it is a sharp reversal of the direction of education policy for the past 20 years or more. The significance of this change should not be underestimated.
Mike Baker is an independent education expert and broadcaster.