KDE releases beta of Plasma 5.1
Put your testing hats on, Plasma 5.1 has a beta release. The second version of Plasma 5 is due out in under two weeks and now is your chance to test it for bugs which have crept in. It features a bunch of missing features which have been added back such as the much requested icon only task bar.
“can you drop plasma 5 on top of sc4? or do you need to get frameworks and related also going as the desktop?"
I don't understand the question... Plasma 5 is the desktop. And Plasma 5 requires Frameworks 5.
There's nothing stopping you from running a Plasma 5 session and then running KDElibs4.x-based applications on top. Except maybe your distribution's packaging, which may install to /opt or just require 4.x to be uninstalled. But that would be a packaging issue.