I know we’ve covered this before, it’s somewhere in the archives, but a VERY reliable source sent me this tonight:

By the way, there’s been all this talk wondering about whether the Ents will be played by performers on stilts, and while I’m not sure what they are intended for (possibly just to provide a mobile reference point when shooting set-ups involving mixed-scale characters, such as the Hobbits alongside humans, etc.), the Ents will be realised primarily as fully digital characters, with partial full-scale props being utilized.

Verrry interesting