Hey, I am an architectural acoustician/architect!  There are more of us than you'd think, but not a lot more.  Guess I'll comment.

How far along are you, and why acoustics?  RPI also has lighting, which is sort of a more natural fit for architects, but...architectural acoustics is good, too.  (Not knocking it, since I chose it! ;-) )

If you're interested in acoustics, I can think of a few other schools in the US (Florida and Virginia Tech, at least) that also have some acoustician-professors in the architecture programs.  There are also schools with acoustics as an architectural engineering specialty, such as Nebraska - you may need some more math classes, however, depending on your educational background.

The main professor (Ning Xiang) at RPI could answer some questions, too - his background is in electrical engineering, which could be good if you want a different perspective.  Gary Siebein at Florida is a registered architect, and Michael Ermann at VT also has an architectural background.  In my experience, you'll wind up taking courses in a variety of schools and getting different perspectives on sound, which can only strengthen your knowledge of the subject - acoustics is pretty interdisciplinary.

No state licenses acoustical engineers except for Oregon, so an accredited engineering school education isn't absolutely *necessary*, although some consulting firms seem to prefer engineers (maybe that's all they've found!).  I think these are usually electrical or mechanical engineers (Penn State, Georgia Tech, and some other schools have their acoustics programs in different types of engineering schools).

As a professional note, I find that there's not necessarily a lot of overlap between the two fields right now.  I'm usually either the only architect or the only acoustician - which is good, because it's fun to have a specialty!  I think there is more potential for overlap between these two. 

Mixmaster...thanks for the feedback.  It was very helpful and it gives me a lot to think about. 

I am 26 and graduated in the winter of '08 with my architecture degree and have been working on and off since my second year of studies.  I originally went to school for computer engineering and immediately switched my first semester in. I also freelance for a solar panel company in NJ, producing electrical drawings and single lines for solar panel arrays.

Why acoustics?  I feel it would be a great pairing with architecture allowing me the ability to consult and specialize in design development and specifications for concert halls, theaters, studios, etc.  I am really looking to set myself apart from others who strictly have degrees in architecture.   My worry is I'll end up becoming just a drafter and that certainly is not a long term goal of mine.

My other issue is my interests and aspirations are constanly changing so I'd like to stay as diverse and pliable as possible. 

Well, you won't be a drafter, but you probably won't really be a designer either!  You'll probably wind up doing a lot more analysis and building science than anything.

I think acoustics is one of those 'found' professions that you don't really think about until you need it (I know I didn't really think about it existing until I started working in it).  If you're just looking to expand your skill set - there are some interesting things you can learn, but acoustics is a small specialty, and you might wind up focusing on that.

Of course, people study things for a lot of different reasons.  For me, after working as an architect and going through the whole architecture curriculum, I couldn't shake the feeling that I felt like I was designing with nothing (or very little).  I sort of lucked into acoustics, and found that the science-y way of defining criteria and being able to analyze and design/adjust space around these needs was a very natural way for me to think (moreso than the whole 'does-it-look-cool' ethos that the more design-oriented people seem to have), and so I continued studying it.

There is actually a lot more to acoustics than concert halls and recording studios.  While I can do a lot of things, I seem to have focused on noise lately - this is a natural pairing with a longstanding interest in urban design and the fact that I also took a whole bunch of planning/GIS classes.  Sound isolation is another major focus, both between spaces and for mechanical equipment - as cities densify, this will become another really major issue in the future.  Really, there are a ton of specialties even within acoustics, and having more of a building-science background is helpful.

If you're getting into another degree just to expand your skill set, I'd also look into something like sustainable building analysis or lighting - you'll also get the building science background, but you may also find that these specialties jive more with your interests.