Its not all about cores, as Bulldozer so amazingly proved...
The Best worrying thing for PC gamers is the GPU architecture it will have..
Appearently it's not to dis-simular to the 7970M
I don't games will be using 8-cores anytime soon. Sony are just thinking ahead.. a lot of modern games are driven by consoles, so if developers see they have 8 cores to play with, they may aim to utilise more than 4..
Games WILL use 8 cores and very soon, both consoles have gone for 8 core low power cpu's rather than quad or 8 core high power chips.
Currently a thread on either AMD/Intel chips can run above 4Ghz pretty easily, both consoles will very likely be running below 2.5Ghz, Jaguar cores have a shorter pipeline and aren't in any way designed for 4Ghz running, they are custom, so they may have managed to add some ability to run at higher clocks but its unlikely that will be what they customized meaning in all likelyhood to get any performance at all from the CPU all game dev's will be going heavily multithreaded, Jaguar is also slower per core, but not by a huge amount at all. Bobcat was 15% behind Bulldozer in IPC, but at effectively 1/4 the clock speed, Jaguar will boost this so it may get around Bulldozer IPC but still at half clock speeds, meaning the performance you'd get from 4 cores fully loaded on a Jaguar would likely only equal the workload on 2 Bulldozer cores, which as you can see from that Crysis graph, isn't going to cut it.
To leverage the full power of the PS4/720 or next, whatever it gets called, they will HAVE to use the 8 cores pretty effectively.
This will almost certainly translate into AMD pretty much owning Intel next year in gaming. Optimising for an AMD cpu and optimising for 8 threads. 8 real cores will likely do very very well in terms of scaling. Of course if a game CPU wise works fine on 8 2Ghz cores, 8 4-5Ghz cores might not bring an awful lot of performance, you'll run out of GPU power at some point, but I wouldn't be surprised to see the 8 core Steamroller walk all over Haswell chips from mid 2014 onwards.
I still wouldn't buy a 8350 unless you have to today, I'd be waiting for Kaveri without question, lower power usage, better power saving, much better chip all around with every big flaw fixed.