[Boromir88]

Its Entish name will be lost forever, hence it’s story will be lost forever, & it will become just a ‘hill’, one among many, & thus nothing special - even as the trees Treebeard has known from nut & acorn, trees with voices & names of their own - stories of their own - will become simply ‘trees’, sources of timber, any of which may be cut down - to feed the fires of Orthanc, or anything else ‘orcs’ may decide to do with them.

An interesting find davem, and it's possible that Treebeard, and the Ents decided to go take out Saruman in an attempt to be remembered for something. If the Ents sit back in the forest, and die out, their language, their stories will pass away. But, perhaps if they do something to help the people's of Middle-earth, will sing songs, and make stories about them.

"Of course, it is likely enough, my friends," he said slowly, "likely enough that we are going to our doom. The las march of the Ents. But if we stayed at home and did nothing, doom would find us anyway, sooner or later. That thought has long been growing in our hearts; and that is why we are marching now. It was not a hasty resolve. Now at least the last march of the Ents may be worth a song. Aye," he sighed, "we may help the other peoples before we pass away...

Treebeard seeing that the Ents are fading away, and will eventually fade away, fears that Ents will be forgotten. That is if the Ents sit back and did nothing. Ahh, but if he helps the other people, then perhaps they may be remembered yet.

Back to my first post about the "green light," within Treebeard's eyes, as well as Bregalad. Perhaps the "green light" is the Ent spirit, or symbolism of the Ents being a race that is fading away. When the Hobbits first see Treebeard...

These deep eyes were now surveying them, slow and solemn, but very penetrating. They were brown, shot with a green light.

When Treebeard considers no thought of Saruman, or helping out Middle-earth, Treebeard's eyes is just a "green light," and represents the fading away of the Ents. But, when Treebeard gets roused...

Treebeard raised himself from his bed with a jerk, stood up, and thumped his hand on the table. The vessels of light trembled and sent up two jets of flame. There was a flicker of green fire in his eyes.

Now the "green light," is a "flame," and there may be hope of the Ents being remembered in history. Then Treebeard suppresses these thoughts, saying he got "caught up in the moment...

At last Pippin looked up, and Pippin could see a sad look in his eyes, sad but not unhappy. There was a light in them, as if the green flame had sunk deeper into the dark wells of his thought.

After Treebeard suppresses his thought, the "green flame," sinks back deeper into his eyes, as if fading, a long with the Entish race. The final occurance when the Bregalad realizes the Ents are going to war...

Bregalad, his eyes shining...

again, hope remains that the Ents will be remembered.

The Ents, as davem has pointed out, don't have Bombadil's excuse to stay out of things. When the Ents have their chance to help Middle-earth, there is a chance that the Ents will be remembered, represented by the "green flame," and "shining eyes." If the Ents pull a Bombadil, then they will fade away, they won't be remembered, and their green flame reduces to a green light, and fades away, deeper into their eyes. Sorry, if it seems a bit jumbled, but the thought just came to me, and I'm spewing it out .