An HTC spokesperson says that their camera technology is advancing so rapidly that they will soon be up to par to "real" cameras. Symon Whitehorn has told Vodafone that "Optical zooming in a smartphone is not too far off at all for HTC" and adds that "within 12-18 months, we'll see huge advances in phone optics."
Many people hate digital zoom because it merely crops the photo, making it seem that it's zoomed in. Real optical zoom will be a welcomed feature for many smartphone users, and may be a compelling one for photography enthusiasts.
Whitehorn thinks that smartphones won't be able to replace traditional DSLR's for a while. He says that they haven't been able to match standalone cameras yet, but they're getting close. He believes that DSLRs will always have a niche for sports, TV shows, etc. He added that "Two years ago, I would have said that phones will never replace DSLRs. Now I'm not so sure."
In general, smartphone users will be satisfied with a brand new HTC One M8 as it is much cheaper than traditional DSLR cameras, and the images taken from a smartphone may seem comparable to professional level cameras.
The advancement of camera optics for smartphones is sure to please many users. Samsung has tried something similar recently with the Galaxy S4 Zoom smartphone, but it has not yet become mainstream. Only time will tell if DSLR quality cameras will become the norm for smartphones in the future.