A phd is actually less likely to help you succeed in practice unless you go into a very specialized area, such as building envelop or material science.  

I had a phd consultant try to talk-down the complicated concept of condensation to me once... it was excruciating. Listen lady, I would not be project arch if I did not know at least the basics.

The Media Lab program leads to a lot of industry / entrepreneurial connections and opportunities. It's a much less "academic" environment than other doctorate programs. So I don't agree with the previous posters that it's not a good path for non-academic careers. However, I wouldn't recommend going through the media lab if you intend to be an architect. It's so tangential to that. I know dozens of people who have worked there, and I can't think of a single one who is currently practicing Architecture.

If you're interested, though, I can speak to a few of the labs and the work they do.

Why the hell not, if it helps you create a network and valuable contacts. I can imagine you don't mind paying for this if you intend on setting up shop yourself or collaborate on the highest level with major players. I know quite some people who got a post professional degree and they all started their own office and got valuable connections and commissions from that post-professional network. If you intend to just work for someone else or do simple residential remodels etc. it would be a big waste of time and money. If you want to call the shots yourself, just dig that hole a little deeper.

doctor, we need you in the o.r. a.s.a.p. , there's a leak in the roof

I had a co-worker who had a doctorate in architecture and she was doing the same thing I was at the time - BIM production on mixed use

doesnt seem like this thread ended up being very helpful. @Extry, im currently in the same mode of thought, and seems the options are still somewhat limited. Atleast in the northeast. Ive heard Michigan has a program, and I think SUNY Buffalo, not sure if youve found a suitable program or not, would be interested to hear if so.

A bit different than just strictly architecture but WashU has the Doctorate of Sustainable Urbanism. It's not a Ph.D. It seems to be very hands-on and applied within the city of St. Louis. Requires a post-grad degree in urban design, which takes a year or so after your M.Arch. It's designed for architecture students in mind. 

I, myself am looking into it. I am currently getting my Bachelor's in Urban Planning (PAB accredited) and am hoping I can transition to a M.Arch after that. I'm from St. Louis and want to move back, I love it there. And so I looked into programs at WashU. So, we'll see.

The best way to learn architectural practice is to get out there and start working.  If you do it right, you get paid also.

Phd: Piled high and deep. 

If you absolutely must have one, honorary is the way to go. 

Crap, we don't even need a Masters degree for our profession.  Certainly we do not need everyone to have one.  A PHD????  Good lord.

Nothing wrong with a PhD, why all the hate for people that want to study a certain subject or fascination a bit longer?

Yes there is nothing wrong with going to school doing research and writing papers and teaching. But I bet you you will learn even more if you can build a house or small structure on the side.

this idea that education is beneath real workaday people is such a mind-fkuc (and so american). There is nothing wrong or counter- professional to getting a phd to learn something of interest and also having a professional career.

kengo kuma has a PhD and it doesnt seem to be causing any problems with his design abilities. He seems to be able to build fairly well, actually. How many people working for him? 300 or so?

to the original question, AA school has a good ddes program.

I concur with the idea, Will.  

CrazyBut tossing off wholly dismissive generalizations as 'so American' is a good reason many consider academics to be douchebags.  Relax a little.

Back to the OP: a second master's is a good path for many who are so inclined.  You've already ID'd a couple of degree foci, but there's any number of them that augment architecture well.  Planning, business, law, art, preservation, project management, development... none is purely academic, and all are (or can be) helpful professionally.