MacPorts: How do I make py32-scipy not depend on gcc48?
Unfortunately py32-scipy does depend on gcc4.8 as it depends on some c libraries which is a set of numerical routines that are optimised to run on your machine and so I think need to be compiled there.

Normally Macports does not compile but downloads precompiled binaries so you should not need to compile gcc48. So check the vlue of buildfromsource in /opt/local/etc/macports/macports.conf it should be ifneeded. It does do this for me on OSX 10.8 got gcc4.8.

Also check you have the latest ports (gcc48 and the std C++ libraries have caused much comment on the macports mailing lists so will have changed) by running sudo port selfupdate 

You can give py32-scipy a variant to chnage the version of gcc used but that will still need a macports gcc compiler as Xcode 4 does not come with gcc but a program that looks like gcc but uses clang.