Okay, I have to nitpick, both as an anthropologist and someone who has belonged to a Neo-Druid church for years:
There's this great tendency in certain subcultures to use the word 'druid' to mean something almost completely unrelated to the origins of the word. I get slightly miffed by this, kind of like my rant about people misusing and appropriating the term 'shaman'. The main difference is just that ancient Celts aren't around today.
The word druid originally refers to the intelligentsia of peoples in 'Celtic' cultures. The Dumezilian "first function", as it were.
The common usage that I've seen spring up has basically reduced the term to mean 'nature priest', or really just be so watered down as to generally mean that something is animistic in some way. I see this coming originally from Romantic era writings, then later from roleplaying games (I often play a Ranger and/or Druid in D&D games :P) and cheesy movies. Some of the influence comes from the Neopagan and New Age-y movement, in which even there it is usually applied will-nilly, but even in groups like ADF that use scholarship to excuse the usage, the argument is rather flimsy. And of course, most Neopagan Celtophiles have little to no actual knowledge about what indigenous, pre-Roman Celtic cultures were like.
All I'm saying is that the term is thrown around far too liberally, with little regard to history or reality. Do we really mean that the ideal path is one practiced a couple thousand years ago by agriculturalists, and that we have little actual evidence of their practices?
I can make the same argument for Asatru or Vodun at least as easily...but I won't.