two druid elves companions just seems like way too much overlap.
Why?
1) more followers are allways better
2) Jaheira was allready semi-confrimmed trough some interview (mentioned abowe)
3) They know well enough that Halsin is strongly requested
4) Druids are probably most versatile class in the game, so there is nothing stoping you making each completely different
5) 3 Druids party can be OP as fuck

Also there are some arguments about replayability, and people who allready mentioned around here that they play with "single life" > companion died in combat ... too bad, lets pick another one.
Im sory, but i wouldnt say that Jaheira excludes Halsin in any way ... if something suggest we wont be able to invite Bear Daddy in our party, its his level ... our whole party is equal in XP ... but that can easily be changed.
check around 0:50 mark of the trailer.
Daaaaaaaamn! O_o
I thought they are goblins! But you are most likely right!

Awesome! ^_^