I have managed to get them going, at least most of them in CC 32 bit version.
No luck with 64, but I do not care about that.
I have moved the content of the plugins folder from CS5 into CC , reinstalled NIK ( again) and they all seems to be running.
Still, I do not know what Photoshop Server is in the Plugin Preferences.
I used to be able just to select the additional plugins folder in their and that would work, but here I cannot change anything.
It is a most weird dialog, do you have any idea how it works ?