I started to post this earlier, engine, and didn't. Might make me look like an anti-FB troll. :)
I do disagree with this rollout and Zuckerberg is about to get a face plant on this decision. Why? The revolt that will happen when folks discover the Dislike button does not Dislike anything FB (politically or PC wise) agrees with. The real trolls will scream and shout that they want their Dislike to wreak havoc...
Know what? I think he will cave and make that happen, it's called self-destruction. The only value of a vote is user engagement tracking. Has no real value in selecting what is truly useful or what is truly not useful.
And in that NEAR vein... the voting function here at WW is... well, that's being discussed elsewhere (for much the same reasons).
Edit: returned to add that I have never clicked a like button for FB, and do not vote on WW (though I did test it ONCE to see how it worked).
Voting is for elections, not posts or personalities.