Nice work.
So I followed the steps on an XP machine and during the final compilation of Bitcoin, I get this error message:
g++ -mthreads -O2 -w -Wno-invalid-offsetof -Wformat -g -D__WXDEBUG__ -DWIN32 -D__WXMSW__ -D_WINDOWS -DNOPCH -DSTATICLIB
-DUSE_UPNP=0 -I"C:\boost-1.43.0-mgw" -I"C:\db-4.7.25.NC-mgw\build_unix" -I"C:\openssl-1.0.0c-mgw\include" -I"C:\wxWidget
s-2.9.1-mgw\lib\gcc_lib\mswud" -I"C:\wxWidgets-2.9.1-mgw\include" -I"C:\upnpc-exe-win32-20110215" -mwindows -Wl,--subsys
tem,windows -o bitcoin.exe -L"C:\boost-1.43.0-mgw\stage\lib" -L"C:\db-4.7.25.NC-mgw\build_unix" -L"C:\openssl-1.0.0c-mgw
" -L"C:\wxWidgets-2.9.1-mgw\lib\gcc_lib" -L"C:\upnpc-exe-win32-20110215" obj/util.o obj/script.o obj/db.o obj/net.o obj/
irc.o obj/main.o obj/rpc.o obj/init.o cryptopp/obj/sha.o cryptopp/obj/cpu.o obj/ui.o obj/uibase.o obj/ui_res.o -l wxmsw2
9ud_html -l wxmsw29ud_core -l wxmsw29ud_adv -l wxbase29ud -l wxtiffd -l wxjpegd -l wxpngd -l wxzlibd -l boost_system-mgw
45-mt-s-1_43 -l boost_filesystem-mgw45-mt-s-1_43 -l boost_program_options-mgw45-mt-s-1_43 -l boost_thread-mgw45-mt-s-1_4
3 -l db_cxx -l eay32 -l miniupnpc -l iphlpapi -l kernel32 -l user32 -l gdi32 -l comdlg32 -l winspool -l winmm -l shell32
-l comctl32 -l ole32 -l oleaut32 -l uuid -l rpcrt4 -l advapi32 -l ws2_32 -l shlwapi
c:/mingw/bin/../lib/gcc/mingw32/4.5.2/../../../../mingw32/bin/ld.exe: cannot find -ldb_cxx
collect2: ld returned 1 exit status
make: *** [bitcoin.exe] Error 1
Probably something fishy with Berkeley DB, but I'm not clear how to fix this. Thanks for any help.