As far as I know, Benicio Del Toro is directing the Hobbit. Jackson’s out. IF it ever gets made that is, seems to be in limbo.
The movies seem to be as firm as something can be this far ahead of time. It is not scheduled for filming to start until 2010, with main filming to run for over a year, followed by the very extensive special effects and other post production work. Theoretical release dates are Christmas 2011 and Christmas 2012. The theories about the second film are still fuzzy, but likely it will be set in the period between 'The Hobbit' and 'The Fellowship of the Ring'.
I re-read the books -- starting with The Hobbit -- each year (during the heat of the day -- in my hammock) when we camp out. Many of Jackson's scenes (example: the Argonath) will forever be my mental images of the scenes as I read...