So, let's look at another, definitely easier way of running GIMP 2.7.x on Mac OS X: not (semi) natively through X11, but through virtualization. First of all, we need a virtual machine with the latest Ubuntu 9.10 (Karmic), or even 10.04 (Lucid, in Alpha at this time) installed: you can create a 32- or 64-bit Ubuntu VM in VMware Fusion, Parallels Desktop or Sun VirtualBox (which is free). On the Mac OS X integration front, Fusion currently offers the best tools for Linux VMs (including an integrated Unix/OS X windows mode (Unity) that really works).
After having set up the Ubuntu VM (also with the latest updates, etc.), we can begin with the essence of this hint.
Within the VM, we just need to set up the Launchpad PPA (Personal Package Archive) software repository for the unstable Ubuntu GIMP releases; run this command in a terminal window:
sudo add-apt-repository ppa:matthaeus123/mrw-gimp-svnThen, if the standard GIMP is already installed, simply update and dist-upgrade:
sudo apt-get update && sudo apt-get dist-upgradeOr, if GIMP isn't installed (as in 10.04), simply install it:
sudo apt-get install gimpCurrently, the downloaded version seems to be 2.7.1.
Finally, after having launched GIMP in the Ubuntu VM, you can activate Single Window Mode from the Windows menu. If you then use Fusion's Unity view, it will look almost like the X11 version, except there aren't any Aqua-like themes available. (The new Ubuntu 10.04 Ambiance and Radiance themes -- also available for previous versions -- are great, anyway.)
[robg adds: I haven't tested this one.]

