There was this page that shows surveyed mid career pay percentiles by college major, though it has obvious limitations by the nature of the survey (though better than random anecdotes of “X got a BA/BS in ___ and later became a CEO” or “Y got a BA/BS in ___ and never was able to get a career track job”): http://online.wsj.com/public/resources/documents/info-Degrees_that_Pay_you_Back-sort.html .
For pretty much all college majors, the top end (90th percentile) ended up being paid well. But some majors are relatively flatter, with the lower percentiles do reasonably well (e.g. nursing, physician assistant), while others are very unequal, with the lower percentiles doing poorly (e.g. music, art history, anthropology, philosophy), implying that graduates are more likely to be in winner-take-all job markets. These do not seem to be all that surprising.