This is interesting…we hear that the Tolkien estate, which manages all the rights to J.R.R. Tolkien’s works, is shopping around the rights to a TV series based on Lord Of The Rings to various outlets. Even more interesting is the huge price tag they are placing on it, which is said to be $200-250 million – just for the rights.
Such a project would be hugely ambitious and likely expensive to produce properly, which limits the outlets that could potentially take it on. HBO seems like a natural choice, having already done Game Of Thrones, and with it concluding in its upcoming eighth season that may be looking to fill the void it will leave behind (spinoffs notwithstanding.) Another possibility is Amazon, which is looking for its own GoT franchise and has some ambitious projects already in the works. I’d expect any such production to have to run for quite a few years just in order to break even for the rights purchase, which could make it very hard to pull the trigger.
In addition, they would probably have to lengthen to story significantly in order to stretch it long enough, perhaps by integrating a number of other stories of Middle-earth (as flashback storytelling or something like that), but I understand the rights are very limited as well.
At any rate, I think it would be tough to score big with a production that has to live up to and even surpass three great films in order to be deemed a success.