[tom bombariffic]

funny, i had never thought about that before, but to me the first answer was the entwives.
I have always assumed that the entwives live in the shire, although it cant be proved. I have read, in previous strings, quotes that suggest that trees have been seen moving around the shire. There is also a quote from the film

"...the old forest on the borders of buckland. folk used to say there was something in the water that made the trees grow tall...and come alive"

I believe this is from the book, although I admit that when i looked for it in the "Treebeard" chapter and the end of "The Uruk Hai", the place in which it was mentioned in the film, I couldn't find it.

For these reasons, and various others that can be found in the other strings on this topic, I assumed that The Entwives lived in the shire. If they did there is no doubt that Gandalf would have known, and, knowing how mysterious he is, no reason why he would have told the ents - he'd probably decide he should keep out of it and what would be would be etc.

But to come to a long-winded and drawn out conclusion, he may have been referring to the entwives as the power in the shire.

er...sorry to waste all that time.
Bombariffic