On trying to clean my system of unneeded packages via sudo apt-get autoremove it prompts me to remove kdelibs-data. I'm obviously running Kubuntu, Natty that is, and am wondering if this isn't a bug since from what the package manager tells me this is a very much necessary package for many other packages in Kubuntu/KDE. I'm also using the KDE 4.7 SC PPA so maybe this could be the reason.
The kdelibs-data /1/ is/was part of the KDE 3.5 desktop. If you have installed "old" applications that need the support of the KDE 3.5 then you need the kdelibs-data.
If you are only using the KDE 4 apps then you don't need the kdelibs-data.
The KDE 4 is having the kdelibs5-data /2/.