There is already an advantage to using more than 4 cores for gaming with multi player online.
I notice the biggest difference in multi tasking. Just at a Windows level. The way 8 and 10 handle more cores is just so much better. I think 7 basically sharted once you had more than four cores. Remember loads of people disabling HT and cores when BF3 came out.
Devs will probably take Ryzen very seriously. Vishera and BD were fine, but the IPC was so poor why would you bother with it? I mean it was obvious that BD and PD worked excellently in Windows 8 and not at all properly in Windows 7. Microsoft released two patches but quickly pulled them. They simply did not work properly in 7. I could get 2000 extra points in Firestrike on Windows 8.
But yeah, devs will stand up and listen when Intel say so. No matter how good Ryzen may be I have a feeling it is Intel who will basically make threading a thing when they hit back. Which they absolutely have to do. I would surmise it won't be very long until we see 6 core desktop CPUs made to fit in every day boards and not workstation boards.
And when they say jump the devs will ask how high.
I can also see some "hobbling" happening with games. Just like we have seen with Nvidia and AMD some games will simply run better on Intel because the devs have brown noses. And obviously that works both ways, I can see AMD courting game devs too.
But, I must say I really don't mind that at all. There has always been rivalry in games (Dirt 2 on AMD was awesome for example, then you have your TressFX, Hairworks, Gamedoesntwork) and so on.
We've been sorely missing that lately. There have been no "killer apps" on either side.
But yeah, even as I hate to admit it Intel denote what we get and what we get support for.