it was not temporary, 6 months ago, i doubt it can fall now, there is a well built infrastructure now, big investments all over the place, it will not collapse any time soon
when bitcoin will reocover from the last hack and okcoin shit, things will be very interesting, this is just another dead time...
May I ask that what exactly you mean by "any time soon"? A month, year or what?
According to whattomine.com, currently if I buy 10 of those GPU's, I'll be making $20 profit every day right now.
Don't rely on whattomine, it lags sometimes, you can easily do your own calculation, just take hashrates and block rewards from official sources.
As for GTX 1070, in worst case you can mine ETH, but you should be aiming for dualmining or other algos (you'll need to do your own research here).