There are a couple campaigns that are not yet official, but could be if some amount of public enthusiasm arrives.
Both potential candidates have platforms nearly identical to the New Progressive Alliance’s Unified Progressive Platform: http://newprogs.org/unified-progressive-platform-ratified

Michael Fulks (OK-2) (I) championed a 4.3% as an Independent running for U.S House this year.  This in one of the most restrictive ballot access states.  As this one of the highest percentages for an alternative U.S. House candidate, he is considering another more organized run for U.S. House, 2014. Voice your enthusiasm here:
http://www.facebook.com/pages/Michael-G-Fulks-for-US-Congress/264576840226955?ref=ts&fref=ts

Joseph Diaferia (NY-16) (G) similarly ran for U.S. House this year.  He will be running for public office again for 2014. He has not made up his mind yet for which one.  You can contribute to the discussion here:
http://www.facebook.com/VoteDiaferia?fref=ts