Eggs last longer than people think. This is especially true when they are kept in a cold microwave. If a person has any questions, they can always go online and look for information. Most egg producers have information on how long their eggs are good for after the sell by date.
Yes, there are ways to tell how fresh eggs are. One way to do this is to crack the eggs open and analyze them by sight and smell. If they look or smell strange, they should be thrown away. Also, many people believe that rotten eggs float and fresh eggs sink in water.
I don't think this information is new as a spring chicken. Rather than a paranoid attempt to crack the code and carbon date my eggs, I would rather know that there are regulars in place to govern that sort of thing. I know I am being lazy, but I can't get excited about this revelation.
It can be very difficult to tell how fresh eggs really are. Yes, every carton of eggs you buy at the store has a sell by date. However, you really can't tell how fresh the eggs actually are just by looking at them. This is a challenge when buying store bought eggs.