[Farael]

This sure is an interesting topic... but I think there are two points that are not being considered.

-If I'm not mistaken (and I may be) at the Council of Elrond, it's said that a frontal attack on Mordor would undobtedly fail. A lot of eagles flying straight into Mordor would be considered a frontal attack, right?

-Now, even if the Eagles managed to beat out the Nazghul (or their lovely birds, because a grounded Nazghul is not able to fight a flying eagle) avoided the poisonous gases and other such things and were not tempted by the ring... what would stop Sauron from detaching a couple thousand orcs, men and even Oliphaunts to Mt. Doom? or even better, why would HE not be there? If I'm not mistaken, it's in the movie not the book where it's said that Sauron can't regain his shape. I might be wrong, but there's nothing in the book to say that Sauron could not go there and ruin the party for the eagles.

Even if Sauron could not take a human(oid) shape, there would certainly be A LOT of orcs and such things clogging everything up. Heck, I'm sure Sauron would be willing to force the orcs to put up even wooden structures on top of where the molten lava is to get the Ring... and if a couple thousand Orcs die in the fires, whawt does he care? once he's got the ring it's game over.