I don't like the sound of this, and I wish developers would stop trying to copy WoW. I wonder how many more MMORPGs are going to have to fail trying to mimic WoW before they realize it's not the game play aspects that make WoW so successful. If LOTRO really wants to copy something from WoW, they should start by copying their lag-free servers and excellent cross-server instance finder. I'm convinced these are the real reasons WoW remains so popular. I doubt it's their awesome skill trees.
Your post makes an apt correlation though, and Captains will almost certainly go the way of the Paladin if skill trees are introduced, and that's a shame, at least from my perspective. So I definitely agree with you that this isn't a great thing for LOTRO.
Actually, WoW no longer uses trees but a more streamlined linear system of some kind (obviously long after I quit). Apparently the trees were bloated, difficult to balance, and too cookie-cutter. So Turbine would be very late to the party if they're trying to emulate WoW now.