If the memo does truly exist, which we will find out soon enough, James Comey could be in really hot water. Both Rep. Trey Gowdy and Rep. Jason Chaffetz are looking to obtain the memo, including Chaffetz threatening to subpoena it.
Either way, this doesn't end well for James Comey. If the memo doesn't exist, he becomes a fraud who attempted to smear the image of the guy that fired him. If it does exist, it raises serious legal questions as to why James Comey didn't report the incident to the Department of Justice. He's legally required to report any incident of obstruction of justice immediately. From what we know today, that never happened. This means that if James Comey really felt that President Trump was trying to stop the Michael Flynn investigation, he just broke the law (18 USC 4 and 28 USC 1361) which at a minimum would cost him his license to practice law. The real question is that during the conversation between Trump and Comey, did Comey really feel that Trump was specifically intending to stop the investigation. If so, why didn't he report it? If not, and he was just uncomfortable with what was said, then he's looks like a disgruntled guy trying to smear the president's image.