Steve Bannon is now not a member of the National Security Council. While the press scrambles for information, and will probably make up some news in the process, Bannon released a statement informing the media his job cleaning up the mess Susan Rice made was complete.
While many won't believe his statement, his original purpose he described makes sense. When you add the fact Trump is someone that completes tasks, and needed someone he could trust, while Flynn was being replaced, it makes sense for Bannon to step down. If he still has a value to the administration, you'll see him in another position. If not, he'll go on with his successful life.