You know what's funny? If someone asked me what hardware to buy for a next-gen PC then I would have to answer "Sorry mate, I don't know." because I have no idea whats going on at the moment. Will someone who spends 1000 on a Titan be fucked in future EA games? Will he have great performance in games that are optimized for SteamOS?
Yeah, it's extremely frustrating!
For the past 15 years and more I could answer exactly what set up a person would need for a gaming PC.
Now, just as we saved up money for a much needed upgrade in our internet cafe, we don't dare buy anything for at least a few months, while newer games suffer in performance.
AMD to announce desktop CPUs that may be game changers since they will be 8-core (but based on newer tech, not the current ones) and games may be developed for that type of CPU due to consoles, AMD to announce new GPUs but we still don't know benchmarks or price of the new chips, NVIDIA to announce new GPUs which will be completely new technology and not just overclocked renamed cards, and now Steam Machines to be announced, with rumors about PCs going the shared RAM-vRAM and packaged motherboard-CPU-GPU solutions...
Fuck it all, seriously, no one can truly answer what the optimal gaming built will be in a year or so.