Earlier this week, KDE developer David Edmundson described in his blog how KDE would be tied to logind and timedated but not systemd itself, at least according to his claim that "The init system is one part of systemd that doesn't affect us at all, and any other could be used.".
Later, in the blog comments, he clarifies that starting with plasma 5.5, in 6 months, they'll drop "legacy" support, according to a decision taken in the plasma sprint.
Even if one can only guess why there is no formal announcement, it seems clear - unless somehow there is a shim or emulator, not only for logind but also for timedated, in 6 months KDE will be unusable unless you are running systemd. And the blog entry makes it clear that the plan is to remove more and more functionality from KDE and use systemd instead.
(Score: 3, Insightful) by Marand on Friday February 20 2015, @04:35PM
I was actually covering some of that in another response to his original "reinventing the wheel" comment , but it turned into a very long post, so it took a bit to get it typed out and try to check for obvious errors. I forgot to mention Xorg vs XFree86 though, thanks for bringing that one up. A lot of the changes have been licensing related. Or Poettering NIH-related (pulse, systemd).