Coming down the pike… or pipe?
At this point, either is acceptable.
Pike was the original term (derived from 
turnpike); and it means “in due course” or something “to be encountered” in the relatively near future.  However,  the word 
pike isn’t universally familiar.  So it was easy to confuse/conflate it with 
pipe (perhaps evoking the notion of a metaphorical “pipeline”).
Home… or hone?
Home or 
home in means to “aim at” or “close the distance to” a target.  See “homing missile.”  Or “After a few false starts, I homed in on the correct answer.”
Hone means to sharpen.  “I honed the knife blade.”  Or (metaphorically), “She honed her debating skills at university.”  Thus, strictly speaking, one can never “hone in” on anything — because that would mean “sharpen in.” 
Hone, it might be said, is the fancier and more hifalutin word.  So it’s ironic that it’s often used in error.  I.e., the plain sounding 
home was right after all. 
Of course, languages evolve.  So it’s just a matter of time before 
hone in becomes more acceptable (if it isn’t already).