As I blog'd before, dbus+python maybe a wonderful technical choice for input method framework. I discussed with Huang Peng (the author of scim-python), we both thought it's worth to have a try. Huang Peng is an expert in dbus and python, after a short period, the project has grown to a remarkable level. That's the ibus project, licensed in LGPLv2.1.
Huang Peng contributed the dbus server API python binding to dbus community, and implemented gtk and qt input method modules basing on glib-dbus and qt-dbus, then implemented the input method bus system with python-dbus, and ported the pinyin IME from scim-python, added python binding for libanthy and libm17n, then added this two IMEs to ibus platform. Maybe the only missing part now, is an XIM frontend. I only contributed some design ideas :$. ibus leveraged many good designs from scim and imbus, it's a project which has huge potentials, and it's deserved to be named as "the next generation input method framework".
You could check out the latest code from http://github.com/phuang, then follow the instructions on http://code.google.com/p/ibus/wiki/ReadMe to build the project. BTW, the gnome.asia submit would be held in Oct. in Beijing, we may have a session about input methods, and we would invite the active input method developers to have a forum, looking forward to see you!