It's good to know that Himerge is being used on distributions other than Gentoo ; and as long as these ones work with a vanilla-like portage there shouldn't be any problem at all.
Now, Himerge (as some of you have commented) is in an early stage of development; and one of the main goal of himerge is to show Haskell as a viable programming language for GUI's , and how this choice could help for introducing new ideas into GUI's development ; so Haskell isn't really an arbitrarily chosen language for the application , it really plays an important role in its structure and design.
OK, that's just from a developer perspective, now from an user perspective, Himerge is intended to be a simple package manager front-end, offering a clean and straight-forward way of working around portage and some of its tools (like eix) , the main idea is that an user could access most (if not all) of the more important portage command line options, including operations like editing portage configuration files, from this GUI.
About the Himerge current status, we have made some progress on the Haskell team with the transition of ghc6.4 -> ghc6.6 lately , around one week ago we unmasked ghc6.6 and many of their packages, including Himerge , so right now the installation procedure should be more simpler than before:
# echo "=dev-lang/ghc-6.6.1" >> /etc/portage/package.keywords
# echo "=dev-haskell/gtk2hs-0.9.11" >> /etc/portage/package.keywords
# echo "=dev-haskell/himerge-0.13" >> /etc/portage/package.keywords
# emerge himerge
This should be enough for now to get installed himerge , notice how the current version works with gtk2hs-0.9.11 only.
I expect to be releasing a new Himerge version very soon , it will bring many new improvements and it will work with the latest gtk2hs version on the tree too.
Well, I hope you enjoy using this application and don't doubt to send me bug reports
 You can read more in my blog http://araujoluis.blogspot.com