Keeping track of the Technical Previews of Windows Server is important to both system admins and developers. This is the best predictive and advance information available at present.
Mary Jo Foley has covered the tech industry for 30 years. She is the author of Microsoft 2.0: How Microsoft plans to stay relevant in the post-Gates era (John Wiley & Sons, 2008). She also is the cohost of the "Windows Weekly" podcast on the TWiT network.
I’ve wondered why Microsquish doesn’t name their server OS’s a couple of years out - like Server 2018 instead of Server 2016. You know, for breathing room. Is it because they know they’re already obsolete by the time they are released?
MS needs to move away from the 5 year cycle and maybe go to 10. They are not really providing much benefit for the cost.