He's a fan of the series, and IIRC Jackson directing a block was floated as a possibility a couple of years ago, but he passed because he was in the middle of directing The Hobbollox trilogy. Now that the Hobbollox is in the can, and the Shitmarillion hasn't got off the ground, it may be back on the cards.
Which would be jolly good, as Jackson is a great director (not just Lord of the Rings, but some of his earlier films were also very good. Except Braindead - that was just mental).