I just played with it again and got it working with my Qt-2.2.2, so I assume it will work with qt-2.3.0 also. To get it to work you have to uncomment out the $MAKE = 'Qt-2.0'; line in the Makefile.PL. Then it did not fully compile for me caused by some missing symbols from $QTDIR/include/qnamespace.h. My errors were:

pig_Qt.c:355: `WState_FontFixed' is not a member of type `Qt'
pig_Qt.c:356: `WState_FontSet' is not a member of type `Qt'
pig_Qt.c:361: `WState_PaletteFixed' is not a member of type `Qt'
pig_Qt.c:362: `WState_PaletteSet' is not a member of type `Qt'
pig_Qt.c:366: `WState_USPositionX' is not a member of type `Qt'
pig_Qt.c:368: `WState_Withdrawn' is not a member of type `Qt'
pig_Qt.c:378: `WStyle_Reserved2' is not a member of type `Qt'
pig_Qt.c:379: `WStyle_Reserved3' is not a member of type `Qt'
gmake: *** [pig_Qt.o] Error 1
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To fix these I just had to go into pig_Qt.c and comment out the lines with the missing sybmols listed above. Afterthat, it finished the compile. I did the make install. Then I ran through every one of the tutorial programs in the tutorials-2.0 directory and they all worked perfectly.
So, delightfully, I was wrong, the author apparently had it working for at least some version so qt-2.x and hopefully it should not take too much tweaking to get your version to work.
Good luck.