Ross Douthat says exactly what needed saying about Peter Jackson's upcoming The Hobbit and its planned sequel/prequel-to-Lord of the Rings::

[T]he prospect of having them essentially manufacture a prequel – and if it does well at the box office, you know there will be others – leaves me a little cold, and a lot worried. It's not that part of me doesn't want to see a hundred Tolkien adaptations bloom (forget 3:10 to Yuma: how about Russell Crowe as Castamir the Usurper, paired with Christian Bale as Eldacar, in 3:10 to Pelargir?). It's just that I suspect that opening the doors to "prequels" open the door to exploitation and commercialization, and a downward spiral that has the Lord of the Rings: The Phantom Menace and Jar Jar Balrog at the bottom of it. Better, I think, for Jackson to make The Hobbit, and then quit while he's – and we’re – ahead.

Update: Peter Suderman raises what could be a still more pressing question:

Jackson, according to the release, is only set to Executive Produce the films, and that fact that the release made no mention of the possibility that he might direct leaves me thinking that it’s unlikely.... I wouldn’t be entirely shocked to see an upand coming tent-pole hack along the lines of, say, McG or Brett Ratner show up in the director’s chair for one of these films. Why not? Studio execs, with just a few exceptions, have rarely proven themselves willing or capable of supporting genuine directorial talent except as a result of dumb luck, mistake, or losing one of the many complicated Hollywood power games. 

--Christopher Orr