have you looked at f1000.com? they have a lot of good papers that have been recommended by specialists in scientific fields.
also, annual reviews probably has a bunch of reviews on the science behind stem cells.
aside from that i would look for opinion pieces in nature, science, cell, etc. other major high impact journals. those opinion pieces will have been written by people who know what they are talking about, rather than sources like ny times, the economist, and other mainstream journals.