It's updated for latest GNUstep (which now seems to require libgnutls-dev), and is verified to work on latest Ubuntu LTS - that is, 12.04 -- that I've switched to. I've also added installation of libxslt-dev, which was not previously installed in the script.
On a 2009 MacBook, longest step of the installation is (naturally) clang, and takes between half an hour and an hour. I'm quite happy with the experience; while the installation process is lengthy, by replacing compiling step of clang with a precompiled version would probably make the installation speedy enough to make a casual Linux user or a new GNUstep developer happy. For now, however, I'm trying to make sure that the installed GNUstep offers the most features, so installing clang from source is probably not a bad idea. (Depending on how much clang is in flux, that is.)
I'd love it if someone would verify the steps that I'm taking and inform me of any extraneous ones. -- Ivan Vučica - ivan@vucica.net