Code::Blocks is currently undergoing a testing and bugfixing phase in preparation for a new stable release, and I expect that at least it will support Windows 7 properly. 64-bit compatibility is another thing, the program should run fine, but generating 64-bit executables is a different thing, and I ignore if they will provide a 64-bit version of MinGW or not. Not that it's difficult to get such version by yourself, but it's always nicer to have everything configured in one step.
And, of course, if everything fails, you always have Linux as well.