Contrary to what I said previously about there being little hope of Torchwood ever returning I now believe that it is very possible it can be resurrected.  John Barrowman is currently tied up with The Arrow tv show but that may end in the next year or so and John just might want to reprise his role as Captain Jack Harkness in a few more episodes.
I know it is almost five years since we last saw Torchwood but none of the cast have actually said that it has been cancelled.  They brought back The X-Files after thirteen years didn't they so anything is possible!  I certainly would not write it off yet and I hope none of you will either.  I could be wrong but something tells me we have not seen the last of it.  Keep the faith!