As an undergrad making the choice of a coursework-based MS and simply graduating with my BS in the next few months, this could not be more timely.
What makes me want to do get the MS is that my undergrad performance was not stellar. I struggled in the middle of my time in college, and while my grades have rebounded and I have been doing well for myself since, my GPA is pretty dismal. I can't see myself getting into any of the good MS programs around the country, and the easy remedy to this is to staying at my university for another year and getting my MS with the goal of having a much better GPA in order to demonstrate my ability.
That said, if the value of such a degree is declining at the moment, maybe it's a lost cause to redeem my academic credentials.