I quit WoW for LOTRO about 2 months ago. I can't say I know absolutley everything about WoW, but I had 3 lv 70s, and was most of the way through T5 content (we were working on Vashj and Kael).
1) Community. LOTRO has the most amazingly friendly community I have ever encountered in a MMO. When I first made the switch, it was a bit surreal. People congratulating me on a job well done, no stupid bickering in general channels, people that were happy to help you out if needed. You really have to experience it to understand.
2) Questing. Questing is questing. I'd like if I said that the fundamental quest objectives are any different than WoW. However, LOTRO follows the books. But instead of it just being you escorting Frodo to Mount Doom or whatever, it keeps touching on the main plot, and the delving deeper into the lore. I find it fascinating. Instead of just skipping quests and waiting for the "Collected 0/10 thingamabobs" to pop up on my tracker, the quest text is actually interesting. I realize this is highly subjective, some folks might not be into the story, which is fine. The XP rewards from quests are phenominal, as well, much like 20-60 in WoW is now.
3) Graphics. I'm a sucker for eye candy, and LOTR delivers. Sometimes you see things that just look funky, but instead of attributing that to poor design, I think it's a matter of the rest of the game being so breathtaking, that strange things really pop out at you when you notice them.
4) Grouping. Grouping in WoW is basically that someone tanks, someone heals, and the other people just beat the crap out of whatever it is that needs killing. I play a lore master, and I find the grouping to require a much higher degree of strategy and individual contribution. Perhaps it is just like WoW with other classes, with which I have little experience.
5) Extremely geared towards casual players. Maybe this is what you mean by WoW being easy. I dunno, WoW is easy in that any idiot can solo to 70 and still know very little about the game. I can't say that LOTRO is a whole lot different than that, but I find solo play quite fun. The rested XP bonus is VERY nice, and there are always a TON of active quests to be had (you can have 40 active instead of 20, and there are a crapload of them).
In summary, the game is less about spamming your highest DPS skill and hoping the mob dies before you do. It's more about planning out a fight, and figuring out what next move to execute for best results. I can't really explain it better than that. Your initial impression will be that the cooldowns are just punishing and gameplay is slow, but once you have more skills, you'll see what I mean.
If you want to race to level 50 (the current level cap) and spend your time raiding, this is probably not the game for you. Currently, "end game" isn't very involved, from what I hear. WoW's raid progression seems to have LOTRO beat hands down. However, this is a very new game.
If you want PvP, I'd say the same. The PvP system is limited, and if you are a hardcore PvPer, it's just not going to cut it.
However, if you want a nice, relaxing, fun game, with a nice customizable interface and familiar gameplay mechanics, this might be for you.