I don't know. Why the sun should be a big ball of nuclear plasma and the pression of the deep sea enough to crush a unprotected man? I suppose in 4E the surface of the sun is just luke-warm and you don't need to breath underwater or to fear deep pressure, how could you be able to have adventures there, else?
And I've read the articles, you don't need to explain them to me, I understand why they made the changes, i just disagree with their decisions.
and Eberron planes are still place hard to reach and very dangerous to visit, not the easily accesible place for an adventure that 4e planes seems to be.