How Valuable Is A Degree?

There's an interesting debate going on, in Higher Education of course, centering on the value of a degree.  It's a subject I did my best to be helpful about at a local school careers evening last week.  

The question I always get asked is: 'should I do a marketing degree if I want to get into marketing?'  

To which my honest response is no.  

From my point of view, as an employer, I want people with good brains who have studied a subject which develops their thinking skills and knowledge of something broader than marketing.  I know there are good marketing qualifications out there (somewhere) but as a first degree subject I can't see it helps if everyone in our industry has read the same books, studied the same case studies and is taught to think in the same way.  

Surely our whole point is to come up with fresh ideas, challenge the status quo, martial our arguments, persuade our colleagues and measure our effectiveness - to name but a few of the things that marketing and agency people get up to.  

I've canvassed my colleagues on the subject.  Their qualifications range from the highly relevant (Honors in Graphic Design or Computer Science) to the useful (Economics, Phsychology, English) to the total wastes of time  (Sociology, Film & Media Studies).  

What do you think - are degrees valuable in the marketing sphere and if so, which ones?