In the last episode of Star Trek Voyager, Admiral Janeway goes back in
time and infects the Borg, evidently killing the Borg queen and other
Borg.  According to Wikipedia, "Admiral Janeway unleashes a virus that
devastates the Borg, destroying the queen, the Uni-Complex, the
Transwarp hub and most likely the entire 'species'". 
http://en.wikipedia.org/wiki/Endgame_(Voyager_episode)

Is there a consensus that Janeway destroyed the entire Borg species?

Dear Panop

The answer is probably "no".
The Doctor Who's Daleks who were "completely destroyed" many times only to
come back in one form or the other. As long as someone wishes to make films, 
books and TV programs about Dr. Who they will always somehow have to
keep the Daleks alive (as the Doctors greatest enemy)

Same thing with "Star Trek" and the Borg. As the quintessential enemy
in Star Trek, so long as Star Trek series exists, the Borg will always
be be brought back by hook or by crook.

Mongolia

Also note the comments by Q. He was responsible for the initial face
to face encounter between the Federation and the Borg when he brought
the Enterprise D to system J25.

Near the end of the episode when the Enterprise is running for its
life Q states: "You cannot outrun them, you cannot defeat them. Even
if you destroy them, the essence of what they are remains. They will
return in greater numbers. Eventually you will weaken. Your reserves
will be gone. They are relentless"