I contacted Betsy Wollheim a few days back, and here's what she revealed:
Pat will not be delivering the complete first draft until March, and I've only read a few tantalizing sections. We're hoping to publish in April '09. We're planning at least two rewrites.
I'm aware that most of you were hoping for a late 2008 release, but it appears that it's not to be. . . Having said that, I'm glad to see that Daw Books will not rush this one. They obviously want the sequel to live up to the expectations generated by its predecessor, and they will not be publishing a book which is anything less than Rothfuss' best effort.