This means they offer great potential for "regenerative medicine", in which doctors hope they might be able to replace tissue that is damaged by disease.
Parkinson's and Alzheimer's are among the neurological diseases which are thought most likely to benefit from stem cell therapies, but they are also said to offer hope for conditions as diverse as heart disease, arthritis, diabetes, and burns.
But there are both practical and ethical issues surrounding the use of human embryos for stem cell research.
Scientists currently have to rely on obtaining surplus embryos from IVF clinics for their work, while some of those with religious convictions are unhappy at experimenting on and then destroying human life - even if it does pave the way to potentially life-saving treatment.
Despite the high hopes, so far there have been no major breakthroughs which suggest treatments are imminent.
The rodent embryonic stem cells looked very similar to human ones
The two studies do not in themselves offer cures for anything, but independent experts say they could dramatically speed up research if the findings really do stand up.
"In the future it should be much more straightforward to translate results obtained in lab rodents using these epiblast cells into procedures for stem cell therapies in humans," said Professor Harry Moore of the Centre for Stem Cell Biology in Sheffield.
"We would certainly want to use these new epiblast lines to test out the potential of therapies we are developing with human embryonic stem cells."
Professor Pederson himself said he thought the first clinical applications of stem cells were about five years away.
"Those would be very early studies that involve a human individual. I think we can envisage larger scale clinical trials occurring within a decade, certainly."