I think LOTR was about as good a series of movies as Jackson would have been allowed to make. Including Bombadil and The Scourging of the Shire (two of the biggest omissions) would have been a plus point to Tolkien fans but likely a minus point to the average cinema-going man on the street. I think it's usually the case that lovers of a book will be disappointed with the on-screen adaptation; but movies are not usually made for those markets.
As I mentioned above , I find very little wrong, and very little in ways of alteration that I can't accept or understand. The landscapes were amazing and did justice to Tolkien's descriptions of Middle-earth, the locations such as Minas Tirith were just as I imagined them, and all of the major characters were easily recognisable from the books (apart from Faramir). In fact as I mentioned in a previous post, the change of character in this one character was my only real issue. But Gandalf was well played, Gollum was brilliant, Sam Pippin and Merry were all very good. And the underlying humour of Tolkien was also captured, with some great horseplay between Pippin and Merry, and Gimli and Legolas.
The Hobbit is (literally) a different story, and what was an enjoyable - relatively short - story about a hobbit going on an adventure and surviving by wits more than fighting or action turned into another LOTR trilogy, but a much poorer one because much of the material had to be made up.
I think that the tv series will do well on the back of the LOTR license, but I think that Silmarillion fans will be disappointed. The tv show is likely to be a continuous storyline following the main characters, and Silmarillion is more a collection of stories. I think character names will be used, as well as some of the locations and storylines, but in a cohesive continuing storyline. Basically the backstory of what lead to the creation of the Ring and up to the defeat of Sauron.