First, setting the new AS grades accurately this summer is not "a marking problem". Individual examiners mark to a common standard set by the principal examiner; they will not be expected to make judgments related to potential grades.
Second, it is misleading to suggest that "(senior) examiners face a major difficulty in establishing what should constitute A to E grade for the new qualification". The evidence that awarding bodies are collecting will support the judgment of senior examiners in determining grade boundaries. This is designed to ensure that there is no major difficulty when it comes to awarding this summer.
It is quite wrong to suggest that students who do not intend to continue beyond AS may not be as able, or take the exams as seriously, as those who do. This is grossly unfair to students who have put in a huge effort to study four or even five subjects.
Joint Council for General Examiners
Stewart House, 32 Russell Square