I have been compiling 32 bit and 64 bit versions of mingw-w64 for use in Citrus Perl and since November 2011 the compiler distribution has been available separately from Citrus MinGW.
As mingw-w64 does not really have an official binary release I thought it would be useful to have a distribution put together with Perl users in mind.
Included in the distribution is a config file that makes use with ActivePerl simple - just set PERL5OPT=-MConfig_MinGWFP.
The binary distribution is contained in a single archive and includes gfortran in addition to gcc and g++.
In addition to the binaries, there's a full environment for building the compilers from source if you really want to. There are just four 7-zipped files to download and two commands to build the whole thing.
I hope it proves useful.