Question: You may have seen this situation a lot of times: 

A guy answers the question in a comment, but comments are easy to become forgotten. Thus another guy takes the original author's solution and posts it as an answer, which is great for a lot of people, but it is originally not his solution. 

Wouldn't it be cool, for the second guy to offer the credits to @OriginalPoster?

Example: [Glassfish DeploymentException: Error in linking security policy for](https://stackoverflow.com/questions/7322476/glassfish-deploymentexception-error-in-linking-security-policy-for/18699520#18699520)

Answer: 
If they wanted the reputation (or honestly, even if they didn't) they shouldn't have posted an answer in the comments; they should have posted an answer.
No, "answers" in comments do not need reputation as it is explicit (also probably misguided) choice by author to not create real answer. The very common reason to post answer in comments is to explicitly avoid reputation loss on partial/unrelated answer for unclear questions.

If actual answer is 100% copied from the comment it should be marked community wiki and mention author of the original source. If answer just happen to have the same idea (whether inspired by the comment or independently arrived to the same solution) there is no additional requirements to cite the comment.

See also [Comment Poaching](https://meta.stackoverflow.com/questions/269913/comment-poaching)