Just installed the Ubuntu 9.10 Beta and perusing the menus and I find under System ==> Preferences ==> IBus Preferences. Clicking on it causing a dialog:
As far as I can tell IBus comes from here.
From what I can tell it’s an input framework that is probably some way of enabling easier non-english language input… Not sure though.
It’s a replacement candidate for SCIM, an input method primarily for Chinese, Korean, Japanese, … language users.