Whilst the growing cells do not suffer from any pain, many people believe that it is wrong to do this and hence, despite how much embryonic stem cell research could help ill people, it is an incredibly controversial topic. In general, the US Democrats are the ones that think that it is a good idea, whilst the more traditional Republicans in general believe that it is disgusting and must be stopped.
The reason why there is so much interest in embryonic stem cell research is that when cells are taken from an embryo, they are not 'programmed' to do anything in particular. This means that scientists can use the cells to grow organs, body parts, skin and help other parts of an otherwise damaged body to repair itself by providing the body with cells that could literally be turned into anything human.
There will always be disputes over this practice but it seems that experiments are going ahead with both embryonic stem cell research and the less impressive adult stem cell research.