This build will last you at least 2-3 years gaming at higher settings. Then you could either cuild a new haswell/broadwell build(Intels upcoming cpu's) or get another 7970 to crossfire. I personally would keep this build for 3 years then build completely new. The 7970 will last you a long time
I don't think I would buy a new PC after 3 years of this, simply due to the cost of it. But I would defently upgrade it to try and achive the highest possible outcome of it in the future
Its going to last quiet a while. Probably 6 years at the most. Upgrading graphics cards is a waiting game. Once your game starts hitting the 30 fps mark at the highest graphical settings on games that are releasing, it's about time to upgrade the GPU.
It will stay with you for quite a long time. Maybe in a few years you may need to upgrade stuff, probably the CPU( or you can OC) and HDD if your old disk fails. A 7970 is plenty powerful. More than enough for any game, plus the fact that you have that sweet PSU, giving you the possibility of XFire( OR you can OC)
I will upgrade once the games start hitting a fps which will decrease gameplay. But the problem I have is,
Will new GPUs / CPU's use other sockets? As right now LGA1150 is the most common one, but I have no idea if that would change in 1year? 2years 3 years?
Current Intel CPUs use LGA1155, and they will use LGA1150 next year for Haswell. I suspect they will hold on to it for 2-3 years, 2 if AMD doesn't do well again, 3 and above if AMD does.
Speaking of AMD, they stated that they will keep AM3+ for 1-2 more years.