I think Zen won't initially impact the mainstream or gamers as much. The 8 core 16 thread sunmit ridge and 32 core 64 thread naples part will be most useful for workstation stuff such as
- Digital audio workstations/music production
- 3d models, rendering and video game development
- Software Development, building applications from source tar balls. Building applications in IDEs.
- Video editing and production, rendering, encoding, handbrake for converting makemkv blu ray backups.
For gamers the Core i5 series and AMD FX series are still great for games and the prices will only get better as time goes on. A Core i7-6900k or AMD Summit Ridge 8 core 16 thread only provides benefit in games with large maps like strategy games, tycoon games, or city builders, but not the majority of games though. AMD to better meet the needs of gamers should have a lower power and lower cost FX and a higher clocked quad core Zen and maybe a quad core Zen with an integrated Vega GPU that can crossfire with a dedicated Vega GPU.
For servers AMD already is planning products but is remains to be seen if they can make a significant dent as this Intel's biggest golden goose by far.
For Ultrabooks, Chromebooks, convertibles, mini desktops, HDMI sticks, and Windows tablets class products. AMD needs something to compete with the ULV core i series, Intel Atoms and Core M products. I think AMD can crack this egg but this is a harder egg to crack. ARM will probably be a better competitor in this area. I would love a 8" tablet with an active digitizer and AMD processor and graphics.
For essential products or low end computers such as the Celeron or Pentium series, AMD has competing products but maybe Zen plus vega can bring needed improvement in this segment.
Finally another area that will be hard for AMD to crack is Intel's laptop grade full voltage core i Series processors. Maybe improved APUs can help here, but this is by far the hardest egg of them all to crack. The laptop Core i5 processor is ubiquitous it will be hard to compete in this area.
My .02 Federal Reserve Notes.