OS X Server’s rate of improvement has slowed in recent years, though Apple is hardly ignoring it. It did get a full Yosemite-style visual overhaul, after all, which suggests that Apple cares about it enough to keep developing it in lockstep with the consumer version of OS X. The continuous addition of features and fixes over the course of the Mountain Lion and Mavericks releases of Server suggests that Yosemite Server will continue on in slow and gradual but still active development.
If we were going to worry about the state of the Mac server in 2014, our primary concern would actually be hardware. First they came for the Xserve, and I did not speak out, because Apple was clearly not going anywhere in Windows- and Linux-dominated enterprise-level server rooms. Then they came for the Mac Pro Server, and I did not speak out, for the cheese-grater Mac Pros were far too expensive to be practical for the new home-and-small-business focus of latter-day OS X Server. Then they came for the Mac Mini Server, and there was no one left to speak for it.
OS X Yosemite Server reviewed in-depth by Ars Technica’s Andrew Cunningham.