I hate to be a parade-rainer, but I can't get excited about this set at all. I tried to do a draft of it on DraftSim and actually just gave up after a few picks. I like LotR and I like Magic but the idea of combining them just doesn't appeal to me. I especially don't like Wizards' attitude of "actually, our market research says you guys love this stuff so shut up".
If the set were silver-bordered or something I could just ignore it, but these cards and mechanics are definitely going to poison formats I care about. (Mostly I'm worried that the Ring-bearer stuff will be too powerful in Pauper, and will lead to the bannings of other cards that were fine before.)
I'm fine with the Adventures in the Forgotten Realms set; I thought it was well-designed, fun to draft, and didn't introduce anything horrible. But I haven't really liked or been interested in any of the other crossovers between Magic and other IPs. I see that two IPs I used to like (Final Fantasy and Assassin's Creed) are scheduled to get the Universes Beyond treatment next year. Don't really know how I feel about that; guess we'll see what they look like when the spoilers start to come out.
Actually... I was thinking more about why I don't like the "Ring tempts you" mechanic. Partly it's because it's such a mistake flavor-wise. Every time I read "The Ring tempts you" on a card, my brain still thinks "oh, better be careful with the drawback there" even though I know full well that there is no drawback. How the hell is there not a drawback?? That's, like, THE essential characteristic of the One Ring. The 2000 LotR co-op board game did a great job of designing a Ring mechanic that players still use despite the danger. It's hard to believe that WotC couldn't do it.
But more than that, I realized that I actually dislike any mechanics that make you keep track of something that isn't represented by a permanent and can't be directly interacted with. The Monarch, the Initiative, the City's Blessing, the day/night cycle, etc. It wouldn't be so bad if there were a way you could turn those things off. Some card or effect that says "it is no longer day nor night" or "nobody is the Monarch anymore" or "reset The Ring to level 0". That would give you some power to try to hate those mechanics out of your metagame. But there's nothing like that.
Sorry for being so negative. In the spirit of saying something nice... I do like seeing Amass come back, and get expanded to different creature types. It's a fun, fair, and flavorful mechanic; I enjoyed it in War of the Spark and I'm excited to think that we might see it again in some future Standard-legal set.