So finally I saw the latest teaser trailer for the hobbit 3 (and also the new Mockingjay trailer).
Both seem good.
And if you want to hear a really interesting and funny talk about Tolkien and trees, try this old one by Tom Shippey:
"Trees, Chainsaws, and the Visions of Paradise in J.R.R. Tolkien" by Tom Shippey from ASU English on Vimeo.