I'm not sure I would notice if Peter Jackson directed. If you take away his big budget and WETA, what really makes Jackson's directorial style stand out? When you see a Sam Raimi film, you usually know it's a Sam Raimi film; it has a clear signature style. I just don't see a unique signature in Jackson's work.
Over-long, self-indulgent films in drastic need of editing?
In all seriousness, I'd love to see him direct Doctor Who. If they went to the trouble of shooting in NZ, it would be similar to the US shoot for series 6, so they'd make use of the location for several episodes and a broader arc. I wonder if Weta would be contracted?