I think SciFi will wind up picking it up after Season 2 of Doctor Who airs.
If they will air Battlestar then they will air Torchwood.
Oh and incase anyone is still scratching their heads about the Babylon 5 reference:
With Torchwood 4 being "missing" and Captain Jack saying "we'll find it someday", this could be Russell T. Davies' tribute to J. Michael Strazynskis show "Babylon 5". Of the 4 previous Babylon stations, Babylon 4 disappeared mysteriously - it was later found to have dragged into the past by a time rift. Strange parallels here to Torchwood 3 and Cardiff's mysterious Rift energies - will this be a major threat later on?