Recently, I was working on pushing Mono UIA stuff into debian/ubuntu, but being accepted is a really long way to go. The packages need to be reviewed by Debian Mono Group hackers, and they were mostly working on geting Mono 2.4.2 uploaded, UIA stuff are not in a high priority.
For those who wants to use Winforms apps on GNU/Linux, you can get packages as deb or rpm without compiling by yourself. Currently we have 1.0 release. You can get:
http://download.opensuse.org/repositories/Mono://UIA/MonoOpenSUSE_11.1/ (for openSUSE 11.1)
you will need to install mono-uia, mono-winfxcore, uiaatkbridge, uiautomationwinforms in order.
you have to add my PPA to your /etc/apt/sources.list, import key and get refreshed, and install
libmono-uia3.0-cil, libmono-winfxcore3.0-cil, libmono-uiaatkbridge1.0, libmono-uiautomationwinforms1.0-cil libmono-uia3.0-cil, libmono-windowsbase3.0-cil, libmono-uia-atkbridge1.0-cil, libmono-uia-winforms1.0-cil in order.
Feel free to contact me if there are problems/questions/concerns etc