Do you have a reference for it being certified for "safety of life" applications?
The announcement that the EGNOS ‘Open Service’ being operational from 1st October does suggest that it is cleared for action but agree that IO540's further search on Google shows that "open service" does not yet mean safety-of-life operations. Hopefully next year!
In the meantime, like IO540, I have been monitoring the accuracy of EGNOS augmented GPS altitude for some years against a rad-alt and have to say it is incredibly accurate when, for example, doing a cloud break over sea. Certainly within 10ft which is more than can be said for the pressure altimeter which can be up to 200 feet inaccurate (not surprising as it set to the regional pressure).
Drambuster