Melomoth's recent article about playing a warden in Lotro caught my eye so I decided to roll a hobbit warden and have a look for myself.
I got my warden to level 6 in about an hour of playtime. This is not enough time to get more than the briefest idea of the class but it did at least allow me to sample the gambit system where combination of three basic keys are used to launch a wide range of higher level skills. I have to agree with Melmoth it is very very clever and I loved it.
One big surprise for me was that there was a lot of button mashing going on because each gambit requires at least three key presses and all the skills are on short cooldowns. Its not mindless button mashing however - you need to be constantly thinking ahead and planning the gambit you want. It is high speed tactical play which contrasts with the low speed tactical play of a Lore Master. I imagine this makes playing a Warden quite intense at higher levels.
I was also surprised that the Warden's signature Javelin weapon seems underused. At level 6 it is really only used for pulling because all of the gambits require melee range. Perhaps this changes at higher levels.
I cannot really comment on the wardens role in groups - I imagine they are a "hard to hit" off tank / damage dealer but they may have other roles.