There won't be a gaming Mac for a very simple reason: gaming hardware is a niche market, and, the Mac Pro aside, Apple doesn't do niche markets. If you add total 2014 profits from both Asus and MSI you get what apple made in 6 days, and that's assuming that 100% of their profits came from gaming hardware, which is, obviously, wrong. I'm pretty sure if you added together all of the gaming profits from every gaming hardware company, and included all the CPUs and GPUs bought by gamers, you'd get, maybe, a month of Apple's profits.
The old Apple almost died more than once because it was a niche company, and those of us who remember the bad days when Jobs was at NeXT know that Apple survived by the skin of its teeth and the dedication of its users. I don't think we will ever see Apple's management put it into such a position ever again. We may all have out problems with the way Apple is doing business now, but you can't argue with the financial health of the company.
That aside, gaming on the Mac also gives a real chicken or egg scenario. Let's say Apple introduces the gMac tomorrow: i7, 970/R290, good cooling and no thermal throttling. What would you play on it? Of all the games I play, only X-Plane is cross platform. There's no Project Cars, no Fallout 4, and no GTAV. Apple would need to convince the publishers there are enough gMacs out there for their ports to. But, for people to buy them, they'd need a large library of games, which takes us back to convincing the publishers to buy them, and on and on.
Oh, and the iMac is terrible bang for buck. It thermal throttles almost immediately.
[doublepost=1453581385][/doublepost]
No they won't: no one builds a gaming machine with workstation parts. The current sweet spot for 1080 gaming is an i5 and a 970/R290. For 1440 you just need a better GPU. 4K is still a bit of a stretch without going SLI 990s. You don't need to pay out for workstation parts, and I doubt you ever will. And you only need an i7 if you're running one of the few games which really benefits from HT.