20-Year Prospect
Stem cell research is an important and growing field that is less than twenty years old. Some scientists already believe that stem cell research holds the key to safer drug testing, toxicological and pharmaceutical practices, artificial organ harvesting, and personalized medicine. Stem cell researchers will spend at least the next twenty years attempting to make good on those promises.
The bottom line is you'll be fine and employed for years to come. Depending on the political climate in the U.S., though, you may be relocated beyond national borders. Singapore, northern Europe, and Japan all appear to be likely candidates (source).