While the clock has started ticking on the 3.5 release grace period for Guidelines updates, I would like to discuss formalizing one other _doing_it_wrong() issue that has been implicitly enforced for some time now: use of query_posts().
Would anyone be opposed if we formally added query_posts() to Theme Check as a required stopper?
To understand why query_posts() is always inherently _doing_it_wrong(), see @nacin‘s WordCamp presentation You Don’t Know Query, and this great WordPress StackExchange answer by @rarst.
In short, if you are creating secondary queries, you should use WP_Query(), and if you’re modifying the main query, you should filter pre_get_posts.
Thoughts?