This will wendell.

From Mefi Wiki

A comment within a thread that insinuates that a front page post may be weak or too contentious for the community and will not lead to a productive discussion. It is a play on the popular comment "This will not end well" or it's sarcastic variant "This will end well."

It began when user wendell congratulated the community on not posting a NewsFilter item in MetaTalk and "officially warn[ed] anyone considering doing something like that it will not end well." Moderator jessamyn quickly noted that "end well is an anagram for wendell."

Fifteen minutes later a user made the post to the Metafilter front page, and user nkyad corrected yhbc's "end well" comment with, "I believe you mean This will not wendell." The front page post was subsequently deleted but other users continued the phrase in future threads.