Happiness or something else?

I've been watching the surge in happiness psychology offerings - the websites, the coaching programs, the university degrees. Seeing the proliferation of interest and academic intelligence about happiness raises questions around the measure of a life - is it happiness or is it meaning? Is it something else entirely? To the nihilists and even the tantrics, there may be nothing at all, no valuation differentiating between one lifetime and another. What would the likes of karma yogis such as Dr. King or Gandhi say? What do you think?