I do not recall seeing a post where we can upvote comments on this forum before, but this seems to be available.
I have enabled post voting on this thread.
2 Likes
Does that mean that you can also vote on answers?
Edit: The answer is yes.
Whoa, wild. I had no idea discourse could so easily become Stack Overflow. I don’t think this was intentionally enabled; I didn’t know this was possible.
It feels discombobulated to me to have some arbitrary topics have such hugely different behaviors at the behest of OP. We could decide to make all posts in a given category default to having post voting enabled, but I’m somewhat inclined to disable this unless/until we have a better vision on how we should use it.
Interestingly, it appears that the moderation tools do not allow us to retroactively enable or disable post voting. It also appears that we cannot mandate that voting is on or off in a given category; we can only change the default new topic behavior.
Personally I’d very much prefer if this was disabled outside of special categories… I come to discourse precisely because I like the flow of discussions and it doesn’t feel like stackoverflow.
It would be great if you could see the names of the voters, just like you can see the name of the “likers”.
For research purposes only, I’ve downvoted some of the replies so far… 
Edit: I see that you can see the voters’ gravatars! That’s better than Stack Overflow…
Edit 2: You ~can’t~ can eventually see the voters’s gravatars on your own posts… ~?~
It can be sorted by “Activity”, default seems to be by “Votes”.