Guys I was able to compile KDE 4.11 on my Slackware 14. I downloaded the sources from +Eric Hameleers
's mirror as he provides the Slackbuild scripts too. This is the link for the sources http://taper.alienbase.nl/mirrors/alien-kde/source/4.11.0/
These are the steps that did in order to have it compiled successfully.
I had to download, compile and upgrade these packages from the Slackware-current file tree: raptor2-2.0.9, rasqal-0.9.30, redland-1.0.16, gpgme-1.4.1 and grantlee-0.3.0.
Also I had to install these packages from Slackware 14 doxygen-18.104.22.168 and libassuan-2.0.3. I installed linuxdoc-tools as well but I think that this one is optional.
Then I removed the previous packages from KDE 4.10 that I had in my machine.
The sources provided by +Eric Hameleers
contain three folders: deps, kde and kdei.
I ran the script updates.SlackBuild in the deps folder. To compile and upgrade the dependencies akonadi, attica, shared-desktop-ontologies and soprano.
Then in the folder kde I ran the script KDE.SlackBuild to compile all the provided KDE applications and some extragear.
And in the folder kdei I kept only the files with the pt_BR translations as this is my native language.
Now I have KDE 4.11 running on my Slackware 14 64 bits. The networkmanagement plugin is not working because of a library that is not used anymore in KDE 4.11. I am using the wicd-kde by now until I have some time to upgrade the NetworkManager and build the new networkmanagement plugin.
So ... if you want to compile KDE from the sources you won't have any troubles if you follow these steps. Just make sure to upgrade the packages that will be needed and it will be ok.
I will not provide the binaries by now as I don't run a full install of Slackware and I am not sure that the packages that I compiled will work out of the box in another machine. I plan to build two VM's (one 32bits and one 64bits) with the full install and then compile to packages so I can provide the binaries in a later date.