You guys should proud of that many people speak highly of Code::Blocks as it is really a good and free/open source IDE. And I also agreed with it and it's my favorite one. But currently, many large projects, no matter open source or close source, free or commercial, Code::Blocks is seldom used(except Code::Blocks itself). Despite the cases of commercial projects, I think the key that why so many free software projects choose Makefile other than any other IDE is:
1. For a free software, customizability is very important, but many IDE(Code::Blocks included) is difficult to deal with it.
2. Free software is usually distributed in source code, however, it is not smart to make the source code itself depends on an IDE. Actually a Makefile with some shell script is enough.
The customizability is reflected in that many open source project have many build option. Currently the project manager in Code::Blocks is similar to VS. One project may have several build targets. But sometime we want our project have several build option, for example, static/shared, ansi/unicode, we will have to add static-ansi, static-unicode, shared-ansi and shared-unicode these four build target to our project. But actually we just need two options, that is, static or shared, ansi or unicode, and for each option we could have more than two choice. So that a OPTION-ORIENTED project manager other than a TARGET-ORIENTED one is needed for a IDE to improve customizability of projects. For example, a project could have several option, just like we build a software from source code, we may specify many build option in configure script. Each option may define a macro for testing if itself is enabled, turn on/off some compiler option(e.g., -g for debug build, -O2 for release build), and even change the name of output binary.
And we also need a way to generate Makefile. I recommend CMake. Autotools always test some very very basic routine such as strcmp and do many unnecessary things. Directly generate Makefile may lose chance to check dependency.
I don't think my idea is very fresh, maybe someone said something similar here in Code::Blocks forums some months ago. The change may be difficult and take very a long time. I don't expect it could come in few days, but I advise you to make it one of the long-term goals of Code::Blocks. Or if you're just doing it now, I will be happy to know it.