I guarantee that 99% of the people outraged about racial and cannon purity in this show have never read, or cared about Tolkien's extensive and somewhat boring writings on these time periods. Hell probably 85% of them never even read the Hobbit and Lord of the Rings, they just saw the movies. Most people are just learning some of this lore right now, so that they can argue on the internet.
The show looks good visually, and meshes well with Peter Jackson's movies. Whether or not it follows cannon doesn't matter so much as whether or not it has good writing and good characters. Since Tolkien's writings on these periods are historical and dry, they would have to make up almost everything whether they stuck to his exact history or not. The new Game of Thrones show is in much the same boat, although they have better people involved and GRRM to lean on.
I will be watching the show, and I hope it is good. It has to be better than Wheel of Time....