That may look like an idea is neat. It's certainly unusual.
My opinion however is it's another marketing gimmick from an industry whose actors have trouble to differentiate each other. This may appeal to hipster and gadget freak, but it won't replace the timer.
Especially the timer beeps so you know your eggs are ready even if you're doing something somewhere else in the house, whereas this ink, you need come back to your nest^H^H^H^H kitchen to verify the color of your eggs.
Self-timing egg: "David Pescovitz:
The British Egg Information Service developed an egg emblazoned with an invisible ink label that turns black when the egg is cooked. The new eggs will go on sale this fall. From the Times Online:
All you need to do is decide whether you prefer your eggs soft, medium or hard-boiled, and buy accordingly.
A spokeswoman for Lion Quality Eggs, the service's quality assurance scheme, said: 'We had a lot of inquiries. We said OK, this is a big issue -- people can't even boil an egg.'
(Via Boing Boing.)