I don't have too much experience with this class, usually preferring Clerics over them in Pen and Paper games (freakin' hippies) and having spent the majority of my CRPG days playing BGI (where again, Clerics are better than Druids).

Now that I'm really dipping into IWD2, I'm starting to see Druids in a whole new light. Their spells are very different than Cleric spells, not like they used to be. The new spell list shows that Druids are now not only different, but very powerful in their own way!

I used to think a party needed at least one healer, Cleric or Druid. Now I think a party needs one of each of these guys, in addition to the arcane spellcaster.

Anybody else feel this way?

A party doesn't NEED any specific character, given that you can solo most games (incl IWD2) with any class.

Druids are cool but the main gripe with IWD2 is the seemingly imbalanced shifting skill. The shape shifting is mostly pointless, unless you get the improved shapes mod, at which point the shapes become TOO powerful. So, either way, one the druids main skills is taken out of play.

To add to what HB said, there is another way in which Druids have been shafted. And that is via the Cleric's ability of Spontaneous Casting.
This effectively means that Clerics have twice as many spells as a Druid.

The question of whether to choose Druid or Cleric can only be answered by your style of playing.
If you are the type to buff up, walk up and start hacking bothering about healing lateron, Cleric is more suitable.
If you first summon and then use spells to do damage indescriminately and from a distance, take Druid.

It is no longer like in BG where Cleric and Druid spells were both variations within the same pool of devine magic.
Now their use is quite different with Clerics focussing mainly on buffing, healing and summoning or damage spells are secondary (altough still powerful). Druids are exactly the opposite.

Taking both does not necessarily mean overlapping of work. Neither is taking both necessary.
Again, decide your playing style and choose accordingly.