The virus mutates with every new outbreak (and several times within an outbreak) which is why it has varied from a 95% kill rate to a 70% kill rate and change in kill times etc. However it has not mutated to develop any new methods of transmission. Additionally it wouldn't be that hard to achieve. If I had it and sneezed onto you you could catch it due to the bodily fluid transmission.From what I have read on the BBC (Which has been discussing the Ebola problem for a much longer period of time then american news) the virus hasn't mutated since is inception in 1976, so tomorrow it wont decide to mutate and go airborne.
However all being said and done, at this point in time Ebola is not an important threat to the vast majority of the worlds population due to it's relative isolation. One could also argue that if the US does develop a home grown case that would be very good for the global population as it'd likely force research at an incredibly high pace.
Relative isolation? Infected countries in Africa barely have enough beds to hold all the patients! People are staggering on the streets like the living dead. If this did spread out of the tightly locked countries, it could easily take, poor, impoverished Africa completely. And in such a densely packed, underdeveloped setting, it could easily turn into a pandemic through Egypt into the Middle East. And I'm pretty sure Israel does not have enough hospital beds for 5 people every hour. 120 people a day, 940 per week, 28,800 a month. The healthcare system in cities would be overwhelmed by that amount. You could also say if the virus breaks out of Africa, world research would jump up, and it would come to pass.