No, not yet. Still think it would be a great feature. Either as a part of the ‘Feature Voting’ plugin or just a simple plugin that adds a button to like the first post of a thread to the front page. Would love to get an idea of how difficult this would be to build
Mockups
Font page with number of votes/likes shown in left side
How it could work (in this case i imagine disguising the like button as a vote button)