KAider is a KDE4 KBabel (http://kbabel.kde.org/) replacement that I've started in January. (see http://websvn.kde.org/trunk/playground/devtools/kaider/).
My intention is to extend it to the state close to 'computer-aided translation system', i.e. tool that allows us translate more text in less time, and with higher quality.
This includes following my 'maxima': majority (if not all) of actions must be accessible from keyboard, w/o using mouse, because it takes less time to press shortcut then to do things w/ mouse.
All existing CAT systems don't support gettext format nicely, and don't have suitable interface
(eg two panel one, like in Open Language Tools, doesn't suit for translating big paragraphs we have in .po files generated form docbook; if user wants to see context, it could be displayed in a special QDockWidget, with smaller font, etc)

And, of course, they don't intagrate with KDE well.

Short list of features (over what we already have in kde svn):
-project management
-context glossary (+sipping on google translate)
-translation DB (QtSql)
-mode for merging translations for editors (QA)
-scripting API (kross)

See
http://techbase.kde.org/Projects/Summer_of_Code/2007/Projects/KAider
and
http://techbase.kde.org/Projects/Summer_of_Code/2007/Projects/KAider/Introduction