I'd like to see some non-hostile treants too. Perhaps they should be considered something sacred, rather than another beast to be slain.
I like the idea that elven druids use their magic to awaken trees, rather them being result of biome generation.
I wonder should/would they continue to produce fruit and seeds? I guess another part of this is should they be able to produce fruit/seeds on demand, or be restricted to a specific season.
It would also be interesting to see them hibernate during the winter. I'd also imagine them being immobile, it's hard to see them walking around and banging into the branches of other trees.
Personally, I can't wait to burn one down.
Edit: According to Wikipedia,
https://en.wikipedia.org/wiki/Talking_tree , sapient trees were endowed with the ability to prophesise (Is that a word?) the future and were used for divination between mankind and various deities/spirits. I maintain the concept that rather than being hostile, they maintain a peaceful demeanour. I'm however changing my mind on whether the druids should have the ability to 'summon' them. The ability to generate an instant prophet seems a little... over powered. I'd think that the elven deities, or forces, or whatever, select trees to become ents.
I'm still looking forward to burning one down.