How long does it take to film a Who ep? 

I can't imagine it taking more than a week or two.

 That puts an interesting spin on all the rumors that Matt may not be back next season.
And just who is "Miss Leading"?

Peter Jackson directing would be great, but the question would then be: What kind of budget would he have to direct an episode?

 That would be awesome!!!  Don't care about the details.  First Gaiman writing and now Jackson possibly directing.  This show has really earned a lot of respect.  I still have not warmed up to Matt like I did the previous Doctor, but, come on, who can follow up Tennant?  

One TARDIS to rule them all. One TARDIS to find them. One TARDIS to bring them all and in the time-vortex bind them.

I wouldn't read too much into this, folks.  Filming in New Zealand would be prohibitively expensive.  The BBC didn't mind filming in the US because they are working hard towards building up a strong following there.  It's a huge market, and thus worth the increased cost.  So far the two people talking about filming DW in NZ are individuals who are not responsible for paying for anything.

As for how long an episode takes to film, that's a bit hard to say.  From what I gathered watching the extras over the years, they don't film episodes sequentially for the most part.  They've got the entire season's scripts ready from the word go, so they film by location.  All the scenes aboard the Tardis are done at the same time, unless a particular actor isn't available.  Then they'll do a pickup when they can make it to the set.  Same goes for all the rest of it.  I remember one of the extras from the first season mentioning that the last scene to be filmed for that season was the scene from the first episode, where The Doctor and Rose are walking away from her estate housing, and he goes into his speech about how he can feel "The turning of the Earth."  Doctor Who is the most expensive show made by the BBC, so they cut costs whenever possible.

 I've just discovered Dr. Who. Love Smith. It took a bit of time to get used to the tone of the show. I tend to like my genre shows to have more of a serious tone to them. But, I stuck with the show last season and grew to love it. It's can't miss TV to me.

Man, if Peter Jackson directed an EP or two (or 50) it would e sweeeeeeeet!

Bring the filming and production to Georgia! The Walking Dead is already filmed here and the cost is very cheap! Besides, I'd love to be a Dr. Who extra as well! Hmmm... Dr. Who meets The Walking Dead...

*sly grin*

 Have to disagree Wyldstaar. It costs like, $3.50 or whatever the current exchange rate is in NZ skedoodles. We have all the infrastructure, and the crews and equipment. PJ would basically spin his own crew up, so it'd be pretty straightforward.

Probably the biggest incremental cost is to send the actors to NZ. 

I suggest that Jackson is a strong enough brand that they'd contemplate it if there was a decent story they could do.