I know that for quite some time the KDE:Unstable:SC repo didn’t contain any recent snapshots. The repo was used to test the 4.8.0 tarballs and since then no more updates took place. 

However since today that has changed. As of now KDE:Unstable:SC contains a very recent snapshot of the KDE SC 4.9 and the packages got published. As always the target is to provide weekly snapshots of the KDE SC 4.9 and other packages. 
At this moment the kdemultimedia packages (juk, kmix, kio_audiocd, etc) are still on the 4.8.2 level as that the main KDE repository is moved from SVN to GIT. As soon as this has been completed, the packages in KDE:Unstable:SC will be updated with the next possible snapshot. 
I have been running snapshots of KDE 4.9 and I have to say that the stability is quite good. Most of the changes are the rewrite of plasmoids, etc to the new QML language.