That "kills up to 90% of infected people" comment is something of an exaggeration. From reading Richard Preston's "The Hot Zone", I recall that the dominant families of Ebola virus are the Sudan strain(s) and the Zaire strain(s). The Zaire strain will really fuck you up; that's the one which kills up to 90%. The Sudan strain is much less dangerous (statistically speaking), and kills something like 40-50%. There's even a new strain which broke out in a medical research facility in Reston, VA in 1998 which was contagious only to monkeys.
It sounds pedantic and insensitive to point out that some strains kill only 50% when even that number is horrific, and sounds totally incidental to mention a non-lethal strain, but actually the Reston and Sudan strains are more concerning in many ways than the extremely lethal Zaire varieties.
Extremely contagious, quick, and deadly diseases like Ebola Zaire often go too quickly for their own good. They can kill everyone so fast that even if the victims travel or meet an ignorant medical response, outbreaks wind up limiting themselves because the incubation isn't really that long and you certainly aren't moving around to spread the disease anymore once you're dead. Several times major outbreaks in African villages burnt themselves out with only the most rudimentary quarantine measures, and there were some major scares when people with Zaire strain took international plane rides that should have lead to global devastation if the disease were really that efficient in spreading. (It is astonishingly contagious in certain circumstances and certain phases of infection, but its contagiousness to people in the immediate area is only correlated to it's potential global virulence, not explicitly and solely causal to said potential.)
On the other hand, diseases like Sudan and Reston Ebola might become much worse health threats than the exceptionally deadly types of Ebola. Something like Ebola Sudan, which kills slower and kills relatively fewer people, could travel much farther and wider than the Zaire types. There could be longer periods in which people are shedding virus while they're still largely pre-symptomatic, longer periods of disease and recovery where they're extremely contagious but still require medical care and community to some degree, etc. I don't recall whether it applies to Hemorrhagic fevers, but there are also viruses people carry and periodically shed for life, as well, like herpes viruses. So a disease that kills a smaller percentage and presents less quickly/dramatically can be far more dangerous than the quicker, more brutal members of its pathogenic family
Along the same lines, the Reston variety of Ebola could be the freakiest of all, given some bad cosmic luck. Something very closely related to a lethal human illness can spread in birds, monkeys, pigs, etc. until it's downright common, and then suddenly re-develop the qualities to infect and kill humans. Now you have something which can be unpredictably spread by a population of carriers which can't be quarantined or predicted even half as well as you could manage human beings. That's why they follow the development of flu strains in birds, pigs, monkeys, and ruminants every year; you never know when something will show up that could make the Spanish flu look like a weekend with the sniffles.
So in summary, the headline makes Hemorrhagic fevers look worse than they really are (although even the 'nicest' ones are fucking terrifying), and it's actually the gentler varieties that are most likely to fuck up humanity one day.