Switch the symbols, thumbs up/down for good/bad post, plus/minus for agree/disagree. Thumb pointing is rating a performance, not voting to show agreement, while the jump form "me too" to "+" is fairly small. On some boards there even seems to be a convention of replying with "+1" to signify something like "I wanted to say that, too".
I think it's thoroughly ambiguous either way - context will have to do most of the work.
Design sketches
1. Notes on differences between these images and what we're planning on implementing:
2. Meetup widget in sidebar, listing the 5 nearest meetups occurring in the next 2 weeks, linking to:
(something like right-click & "Open Image in new tab" will help here)
3. New headers: