I understand your hesitation, especially with the concept of gambling on the future.
For what it's worth, some games have already received optimizations for Ryzen CPUs like Dota 2, Rise of the Tomb Raider and Ashes of the Singularity.
Although I wouldn't expect many games that have already released to receive optimizations, unless they're being constantly updated like Dota 2 is.
Games have been taking advantage of 4+ cores/threads in CPUs, especially Intel CPUs although perhaps not fully.
Interestingly Ryzen's gaming performance is a bit odd considering the CPU power that is available, it seems optimizations need to be geared towards the CPUs themselves, not just the number of cores/threads they have which is why some games got optimizations for those CPUs.
Here are some examples of the CPU core scaling that can be seen on Intel CPUs.
Battlefield 1
Source - PC Games Hardware
Assassin's Creed Syndicate
Source (PC Games Hardware)
In Digital Foundry's testing you can see the i7 7700K distancing itself from the i7 7600K.
Digital Foundry - i7 7700K Review
Unfortunately I can't say for certain how Ryzen's gaming performance will be in the future, the best thing to work with is the performance we can see now and the gaming performance of today shows that the i5 7600K outperforms the Ryzen CPUs in the majority of games, however they both appear to be capable of delivering 60 fps in most games, even with the 1600x being underutilized.
I guess you have to decide if you're happy with it's performance in today's games, if you are then performance gains in the future as it is better utilized would be a plus.
I'm not sure if you've already seen this but Paul runs some benchmarks and his video provides a pretty good look at the performance of the Ryzen 5 CPUs against the 7600K.
RYZEN 5 REVIEW! 1500X + 1600X Gaming Benchmarks vs 7600K - Paul's Hardware
Holy hell, thank you for this write-up. The performance differential I'm noticing between Intel and Ryzen isn't so extreme in favor of Intel that they're the clear choice for gaming, and the non-gaming applications of Ryzen speak for themselves. The benchmarks you've collected present a compelling argument for Ryzen as well.
Do you have any resources you can point me in the direction of for acclimating myself to the quirks and differences I can expect on a modern AMD processor as an Intel user, if I decide to go that route? Stuff like UEFI differences, things I need to know when shopping for a motherboard/memory, and general terminology differences between the two ecosystems. These are the real hang-ups for me when it comes to considering a Ryzen build.