it may be possible that it is more infectious than ordinary pneumonia but it doesn't appear more deadly, in fact it appears to be less severe in the majority of patients. The mortality rate for hospitalized pneumonia patients, in general, is about 5%, for the coronavirus it appears to be about 3% right now but that number is likely too high because a lot of the less severe cases might not be diagnosed as such.
FYI, pneumonia is not a really a single infectious disease, it is a condition caused by a wide variety of infections (bacterial, viral and fungal) and non-infectious causes. The bacteria that most commonly causes pneumonia is generally benign in healthy individuals, it only causes pneumonia in a limited set of cases with predisposing factors.