Once again the relentless advance of science continues.  You may say neat, but so what.  Well if they can produce type O blood in bulk from this process then an emergency blood supply can be produced ON DEMAND.  Eliminating shortages as well as the possibility of diseased blood.

This is a big deal.

While a few red blood cells have been created from embryonic stem cells before, the ACT team is the first to mass-produce them on the scale required for medical use. They also showed that the red cells were capable of carrying oxygen, and that they responded to biological cues in similar fashion to the real thing.

I am curious if this has any impact on other treatments such as cancer.  What if you could clone someone's blood that has shown resistance to cancer growth?  There could be a source of Reverse-Typhoid-Mary blood supply.