Real quick update for those of you struggling to make GCC ARM 4.7.3 work with CooCox.
First of all, make sure that you when to the Project menu and selected the new toolchain path (e.g. ...\4.7 2012q4\arm-none-eabi\bin) AND set the linker to the new libm.a file in the new toolchain path (e.g. ...\4.7 2012q4\arm-none-eabi\lib\armv7e-m\fpu\libm.a for the Hardware FPU library option)
If you properly configure the new libraries and you are getting a compiler error saying "[cc] arm-none-eabi-gcc: error: unrecognized command line option '-Wl'"
Download this file: org.coocox.builder.ui_18.104.22.168212141638.jar
and put it on your CoIDE plugins folder, e.g. C:\CooCox\CoIDE\plugins, overwriting the one that is there.
If you have other problems, and you're trying to use printf(), then you and I are in the same boat, so hold on for the solution. For now get rid of printf() and try to be more creative about getting data out of the uC.
Thanks to these guys for the help on this one.