Basically, each new arch gets eDRAM+GPU architecture increase (with IPC increase being less than 5%), a shrink, and deployment into HEDT in separate steps so that each architecture can go farther while still offering new products. (4 distinct implementations of the same base architecture, as opposed to the 3 of previous years)
IMO eDRAM+GPU architecture enhancements will form the "new" refresh step to switch from a 2 year architecture lifecyle to a 3 year architecture lifecycle, since the HEDT and Shrink strategies are already rolling.
There will be smaller updates, chipset stuff, video decode/encode enhancements, and the like. But I think that the main focus of of each release will follow along those lines. Shrinks will also likely increase GPU size without majorly changing architecture. GPU architecture + eDRAM changes will be the headline feature of the new "tick."
This is all speculation on my part of course, and not comprehensive of all the strategy. Just as to the differences between tick tock of yore and tick tick tock of tomorrow.
And I hope I'm wrong insofar that increasing core count becomes a regular feature too.