All that matters is whatever is built can adapt to changing needs, be maintained over the desired lifetime of the platform, and perform to specification. Hogwash, all those things can be designed into a non-OO system. You can't tell me that a Java system will work inherently better than a Perl system, or vice-versa. Afterall, they're going to be doing the work, and loving or hating the decision made, not the cms-list folk. Happy programmers are creative programmers are productive programmers.
Success is happiness and happiness is success.
That said, if you hire me for your project, please let me use an OO language because that's what I enjoy most and do my best work with. But it's just as important that they all are made comfortable in the environment they're placed in. Let the graphics people use whatever software let's them swizzle pixels best, and let the writers use whatever apps help them write.