Even in the film the White Rider appears in Fangorn to talk with Treebeard. So Treebeard and the Ents are in communication with Gandalf, who is coordinating the whole attack, or defense really.

But for some reason PJ didn't want to show that the Ents were at Helm Deep.

I thought FOTR was **** movie but TTT was ***.

There wasn't enough Gandalf or Frodo in TTT.
Their dialouge and relationship in FOTR was great.

Not enough Arwen either. ;)

Too much of Merry & Pippin with the Ents.

Too much Gollum for me.
I found his face and voice very annoying.

Yeah, it's actually going to be in the Extended R-rated edition with the Ent's ripping the orcs limb by limb (I'm just kidding, wouldn't that be great though?)