It would be really interesting to see an equivalent study for the UK to this one which is discussed in Fast Company magazine:
What College Degrees Are Really Worth | Fast Company
It certainly looks like graduates from Business degrees in the US do better than quite a few others in the salary stakes and this may well translate to the UK. However, with the increases in fees for degrees which will be implemented in 2012 it will require a large difference the income a graduate receives to pay back the fees.
Professional courses and qualifications, such as those from CIM, could help here - either by helping maximise the salaries of graduates through differentiation or by providing an alternative route to those who choose not to take the University path.