Currently people in developing countries are dying from lack of nutrients. Certainly introducing rice that has been genetically modified contains some risks. However, risks mentioned to the people simply included allergies and "other unknown risks". To me, these do not seem detrimental. Certainly there is already a potential for allergy with any new food. If one is allergic to the new rice, they simply would not eat it. They'd rely on the traditional rice and other food as they already do. Its also been mentioned that a vitamin A toxicity is possible. From what I have read, it seems there is not enough vitamin A or beta carotine that this could be a concern. It may need to be monitored as successive generations of rice are bread, however, I do not believe that to be a concern based on information from the reading, supplemental guides, and other articles I have read. As far as the unknown risks, would the outweigh the current known risk of blindness and death? I do not think so. The people who are eating the rice would carry both the risks (allergy/unknown) and benefits (reduction of vitamin deficiency) of the new rice.
Risks to the environment include both known and unknown factors. There is concern that using GMO rice will decrease biodiversity and may cause problems with nearby crops or animals. This is a risk with any GMO crop. Its also, unfortunately, something we cannot really know until the crop is planted and used. Environmental benefits include reduced pesticide usage, reduced erosion, and better food safety. These things can actually help protect the environment. While loosing biodiversity could certainly be problematic, the environmental benefits may also help preserve the land in areas that have land shortages and food safety problems.
I believe the benefits outweigh the risks in this case.