IMO, Hi Res is here to stay because there is a segment of the music buying population that want it, pure and simple.
Technology never rests. In just about every industry they are always trying to raise the bar, music is no different. Are they always successful? No, but that's never a good reason to stop trying. Bob Stuart is just next up.
I've dabbled in SACD...so far I like what I'm hearing, I agree wholeheartedly with PENG's comment...to paraphase...a good recording is a good recording, the format can't make a bad recording sound good. I haven't heard a MQA recording yet, so don't have a firm opinion of it yet. Right now I would challenge the theory of it becoming mainstream.