Qt is now configured for building. Just run mingw32-make. To reconfigure, run mingw32-make confclean and configure.
C:\MinGW\bin>mingw32-make.exe mingw32-make.exe: *** No targets specified and no makefile found. Stop. C:\MinGW\bin>mingw32-make.exe %QTDIR%\makefile mingw32-make.exe: Nothing to be done for `C:\Qt\4.3.0\makefile'.