Building MIEN on Linux is mostly strait forward. You will need wxGTK, which means you will need the whole GTK+ library dependency tree. On most distributions, you can install wxPython 2.8 for python 2.5 via your package manager. If you can, do it, since it will save time. Barring that, If you have X and GTK packages, and the development versions of those packages, you should be able to build everything else from source in an hour or two.
I have noticed several issues with GUI sizing on Linux. For example, some sash windows start up pulled all the way to one side. The widgets function normally once resized by hand. I understand that this is annoying, and it's on the list of known bugs. Since this class of bug is non-fatal, and hard for me to test for, it may still be some time before all these issues are fixed.
Automatic detection of the number of CPUs is also currently not working on Linux. This should be debugged in the near future.