Pretty much all the CPU intensive tasks I do on my computer benefit from more cores. Compiling, running tons of VMs, FPGA routing, transcoding..
There are games which are well threaded too. And more cores help lift the minimum frame rate.
It's bullshit that we've been stuck on 4 cores for so long in the mainstream. The reason why developers don't bother with supporting more threads is because there is no incentive for them to do so. Zen could provide that incentive. And no I don't mean by capturing majority marketshare, but it might pressure Intel to finally stop shipping dual cores and provide more cores in the mainstream.
8350 is not an 8 core processor really. It's an 8 thread processor. Zen will be a 16 thread processor.
Sandy Bridge IPC and single thread performance would still be a huge upgrade over 8350, and with 16 threads it would absolutely destroy any 4 core Intel CPU in multithreaded tasks. Sandy Bridge with its high OC ceiling is still a pretty competitive CPU, in fact people on Sandy Bridge don't really have that much reason to upgrade. You also have to keep in mind some of the tiny incremental performance improvements over the Intel architectures post Sandy Bridge come from memory speed. Besides I think most people are expecting Haswell level single thread performance from Zen, which is pretty solid.
Also I don't understand the price talk at all. We have no idea how much Zen will cost, AMD has said zero about the price. But if rx480 is any indication it will be disruptive. Because AMD is after Intel's marketshare. So calm your horses.
And finally. Zen is a brand new grounds up design. Even Intel's first Core architecture wasn't amazing. It took a few tweaks to get to the point of Nehalem. Zen is a very ambitious project, there is a reason Intel does their Tick Tock in a way where a new architecture and new process aren't in the same cycle. Because it's not easy to get everything right. AMD is doing their first CPU on 14nm with a brand new from scratch architecture. I would not expect miracles. But that doesn't mean we shouldn't be excited about it, and support it, because we've seen what lack of competition does. 10 core Intel CPU for enthusiasts is $1700. So yeah I am buying Zen..