Quoting from the discussion section of this paper:

"Such data, obtained from experimental animal models, combined with the aerosol decay rates determined in this study, would suggest that filovirus, at infectious levels, may remain a potential aerosol threat for at least one and a half hours. Epidemiological evidence, however, would suggest that during outbreaks, filoviruses are rarely transmitted by the airborne route."

A bit disconcerting.

Let's hope that the "epidemiological" evidence is again borne out.