My main problem would be how much.... "generic" it would feel.
I'll try to explain, I don't want to be a gatekeeper, but to me Lord of the Rings is sacred. The emotional attachment I have to it is immense. They can screw up everything, but NOT "my" LOTR!
That world is so unique, and so perfectly captured by the movies, that when / if I watch a LOTR adaptation, I want to feel I'm really in Middle Earth. No director is required to fulfill the idea I have in my mind of that world, but I want to really "feel" it. I don't want it to look like yet another fantasy show with the cliches of the genre - the female action hero (in this case Galadriel), the love romance (please tell me Galadriel won't fall for Haldebrand, the guy of the boat), the modern looking characters...
LOTR is LOTR. As estabilished not by my personal ideas about it, but by the movies and the drawings of Alan Lee. As long as I get the feel I'm in that world and it's not just another generic adaptation of "just another fantasy story" (LOTR is not "just another fantasy story for me!"), I can forgive some digressions here and there.
For example, I loved Moria. It really felt like Moria from the movies, even though they didn't literally copy it. I guess eventually we'll see the dwarves discovering the Balrog?
On the other hand, I expected elves to be more fair and ethereal than random guys with pointy years. I know you can't all cast super good looking guys, but elves should really be more beautiful and stand out more.... I don't want Legolas clones and Hugo Weaving was definitively not "elf-beautiful", but come on, make them really stand out