Most of the staff at OpenAI have threatened to resign from the company and join Microsoft, which has hired ousted OpenAI CEO Sam Altman and former OpenAI co-founder Greg Brockman to lead a new “advanced AI research team.” In a letter to OpenAI’s board that was reported on this morning by Wired and journalist Kara Swisher, more than 500 current OpenAI staffers say that “Microsoft has assured us that there are positions for all OpenAI employees at this new subsidiary should we choose…