This is already worse than SARS in just a manner of a month.
We also know that of 4.6k cases, 900 approx are in serious/critical condition:
https://bnonews.com/index.php/2020/01/the-latest-coronavirus-cases/It's doubling roughly every 2 days in China, and causing a minimum of 25% to be hospitalized to the point of being in serious/critical condition. Some portion of these will certainly die, adding to the mortality rate.
Moreover, typical course of the illness has dyspnea setting in around 8 days, with mechanical ventilation needed at 10.5 days. Unfortunately, almost 50% of the new cases are from within the last few days, so there is a strong likelihood of seeing a large rise in those critical/serious numbers.
But, the truth is at this point we still just flat out don't know how bad it will be. In perhaps one, but probably about two weeks we will know the critical questions:
1) Has the virus spread from China and is it now causing local epidemics in other countries?
2) Just how bad is the mortality rate?
The big catch 22 here is that, given that this virus is clearly quite infectious and can likely transmit symptomatically and definitely in this with mild illness (who won't go to hospital and continue to stay in population) and has a decent incubation period of 5-9 days...by the time we know the answer to the above questions, it will be too late for effective action from government(s).
In other words, if we don't take drastic action in the next few days, those governments are gambling that both #1 and #2 are in there favor. Which is certainly possible, but that's a hell of a consequence to roll the dice with.