Kdenlive 0.7.7 and MLT 0.5 are ready in my stable series PPA.
http://www.kdenlive.org/user-manual/downloading-and-installing-kdenlive/...
Edit : If you are working with intrepid or jaunty you had a problem because I didn't upload at the same time kdenlive and mlt (this is stupid, I know, but I had more urgent tasks to do with by baby boy and then I forgot to finish the job). During the time lapse any upgrade failed with a missed dependency. Now it's ok and if you reload your package manager the upgrade will be smooth.
Edit 2 : If you are using ubuntu karmic with KDE 4.4, you must use my unstable ppa (ppa:sunab/sunab2)
Edit3 : both ppas have been updated to kdenlive 0.7.7.1

Hi all,
For people having dependencies problems during the upgrade see the edit in the top post.
For the Qt 4.6 problem :
my packages are built against the officially supported version of Kde in each ubuntu version since intrepid. I see some people here mixing my packages with KDE 4.4 from another PPA. But my karmic packages are built against KDE 4.3 : this may result in bugs because my packages are not aware of new procedures of a more recent Qt/KDE.
I could set up a separate ppa for kdenlive 0.7.7 built against Kubuntu-backports-ppa for karmic users or simply rebuild my karmic packages against that ppa but this will force every karmic user to upgrade to KDE 4.6.
edit : for karmic users wanting to work with KDE 4.4 use my unstable ppa, I will rebuild the karmic packages there in a few hours.