Yes, I realize that those were a series rather than movies. I just said movies 'cause well, I didn't think people would care that I was technically inaccurate. Guess I was wrong. Anyway, I don't see how you can call Narnia simply a sequel or prequel to LotR. Of course it's possible it will have a similar cinematic style since the same people are designing the creatures and armies. But remember, it's a completely different target audience, completely different director, different studio (Walden and Disney vs. Newline and Wingnut), inspired by different mythologies (LotR was heavily norse based. Narnia draws from greek and eastern mythologies), etc. etc.
And even if it has the same visual style as LotR, (which would make since, since the AICN clip was focused on weta) is that a bad thing? I mean, Return of the King alone won 11 oscars (a number of the recipiants of those oscars are working on Narnia), a record tied by only two other movies. I'd say that's a crowning achievement, and if Narnia is visually anything like LotR, that'd be great.
I'm not really sure what your point is with the "horror" movie idea. You may recall (if you've read the book) that CS Lewis even wrote "ogres with monstrous teeth, and wolves, and bull-headed men; spirits of evil trees and poisonous plants; and other creatures whom I won't describe because if I did the grown-ups would probably not let you read this book -- Cruels and Hags and Incubuses, Wraiths, Horrors, Efreets, Srites, Orknies, Wooses, and Ettins."
So, yeah, that's just a part of one paragraph of the book this movie is based off of. And the AICN clip was focused on showing the creatures and only the creatures because, well, that's what weta is in charge of. That doesn't mean that they will be overpowering in the movie. If you want one five-minute scene to have all those things described, you've got to make them all. They may just be in there a brief moment of film time, but this particular video clip was showing all of the stuff they have to make for just a short piece of the movie.
But anyway, I think most of us here are awaiting these fine films with eager anticipation, and that's why we've stuck around this particular website, which I believe is a sort of fansite for the movies and books. (hence the domain name)