While users have long pointed out the need for a "dislike" button, Gary Coleman's untimely death comes as the first celebrity passing since Facebook's release of the "like" button to the greater internet (i.e. not directly on Facebook). The awkwardness of having a "like" button on an obituary is obvious. Users don't appear to be too concerned with the unfortunate "like" button, but that may change in the future as more and more negative news headlines get paired up with "like" buttons. Plane crashes and terrorist attacks come to mind.
One solution that sites can implement immediately is to add a setting to their content management system (CMS) to allow editors to remove the "like" button.