What we know so far

The Galaxy S9 will be the first 2018 flagship for the korean giant tech manufacturer. As we all know the S9 is the next to come in the Galaxy S line. Some rumors state that it might not be called S9 after all. If Samsung sticks with the natural sequence it may create an inferiority complex among the consumers, as reported by ZDNet, DJ Koh, president of Samsung's mobile division, commented on the phone's impending release at a press conference for Korean media at CES. Later, the company confirmed to CNET that the Galaxy S9 will indeed be unveiled at Mobile World Congress, which this year runs from Feb. 26 to March 1 in Barcelona.
Evan Blass, who frequently leaks reliable information on tweeter, predicts that Samsung will announce Feb. 26, the first official day of MWC, accept preorders on March 1 and ship the phone on March 16.

What we should expect

One of the most expected feature on the Galaxy S9 will be the fingerprint reader embedded in the display. Vivo has already presented a prototype with an under display fingerprint reader and there are rumors that Samsung may offer it's first Galaxy S Series with this option.
Among the specs listed in a leaked photo of what looks a whole lot like a Galaxy S9 retail box, it states that the S9 will have a 5.8-inch Quad-HD+ sAMOLED screen, dual rear-facing 12-megapixel cameras and a single-lens 8-megapixel front cam.
We know that the next flagship will run Samsung's own Exynos 9 Series 9810 processor, at least in Asia. Given that the Snapdragon 835 debuted in the Galaxy S8, it's quite possible that the Galaxy S9 will be first out of the gate with the Snapdragon 845, which is expected to enable a whole bunch of new features plus battery life improvements. The Snapdragon 845 would give the Galaxy S9 a big advantage, at least on paper, over other phones with killer cameras. In addition to securing bragging rights as the first to record 4K Ultra HD video, Qualcomm says the chip will produce brighter photography and video, reduce noise and make it possible to embed tiny videos within still portraits.

Bottom line

There will not be any major changes in the design are, as we've seen so far in the leacked images.
The most important upgrades will be made in the battery life performance where we can expect 30 percent better power efficiency, 512 GB built in storage that would give the Galaxy S9 eight times the integrated capacity of the 64GB Galaxy S8 and it might keep the headphone jack.
As concerning the price tag Apple has already cleared the way for four-figure phones in the future. And if Samsung delivers on all of the rumored camera upgrades, that would almost certainly push the price up. The Galaxy S9 will be officially announced at the end of February and released at the beginning of March.