The rumor mill has fully geared up, so it seems time for a thread in which the potential HTC-made 2016 Nexus phones can be discussed.
Rumors suggest two phones: a 5" device codenamed Sailfish, and a larger device codenamed Marlin. Both are thought to be produced by HTC. [There's also a report that Google is making its own phone, without an OEM partner--along the lines of a Pixel phone--but that report has been largely discounted.]
Android Police has claimed it knows with 8/10 certainty some specs of the smaller device--Sailfish:
Manufactured by HTC
5" 1080p display (~440PPI)
Quad-core